Research Methodology: A Guide for Researchers In Agricultural Science, Social Science and Other...

Instrumentation and Computation 13

13.1 Instruments

Instruments have become an indispensible part of

modern scientific research; may it be laboratory/

field research, use of one or more instruments is

inevitable. The knowledge of instruments about

their function, principle, and safety measure dur-

ing use is an essential part of research activities.

Thousands of instruments with their variants are

being put into use in research. Everyday a number

of new instruments are being invented and

dedicated for the betterment of the humanity.

One can hardly provide description of all these

instruments at any point of time. In this chapter,

our attempt will remain to provide a brief descrip-

tion of some of the mostly used instruments in

agriculture and allied fields. It must clearly be

noted that this attempt is neither exhaustive nor

any effort to list the instruments. The following

table gives a glimpse of few instruments used.

P.K. Sahu, Research Methodology: A Guide for Researchers in Agricultural Science,Social Science and Other Related Fields, DOI 10.1007/978-81-322-1020-7_13, # Springer India 2013

389

Instrument

Feature

Image

pHmeter

pHisthemeasure

ofthedissolved

hydrogen

ionconcentrationin

a

solution.ThepHrangeof0–14accountsforhydronium

activitiesfrom

10to

1E-14mol/l.ApHmeter

measuresthepHofasolutionutilizing

aglass

electrode.ApHmeter

measuresessentially

theelectrochem

ical

potential

betweenaknownliquid

insidetheglass

electrode(m

embrane)

andan

unknownliquid

outside.Because

thethin

glass

bulb

allowsmainly

theagileandsm

allhydrogen

ionsto

interact

withtheglass,theglass

electrodemeasurestheelectrochem

ical

potential

ofhydrogen

ionsorthe

potentialofhydrogen.

ApHmeter

mustnotbeusedin

movingliquidsof

lowconductivity(thus,measuringinsidesm

allcontainersispreferable).

390 13 Instrumentation and Computation

CaringforapHmeter

dependsonthetypes

ofelectrodein

use.ModernpH

metersdonotmindtheirelectrodes

dryingoutprovided

they

havebeen

rinsedthoroughly

indeionized

water

orpotassium

chloride.Rem

ember

that

aliquid

ofpH

¼4has

10,000more

hydrogen

ionsthan

aliquid

of

pH

¼8.Thus,asingle

dropofpH

¼4in

avialmeasuring400dropsof

pH

¼8really

upsetsmeasurements!Rem

ember

also

that

thecalibration

solutionsconsistofchem

icalbuffersthat“try”to

keeppHlevelsconstant,

socontaminationofyourtestvialwithabuffer

isreally

serious.pHmeters

havegotextensiveuse

inthefieldofpharmaceutical,agricultural,wine,

andfoodindustry

such

asmanufacturingofsoftdrinks,butter,andyogurt.

Therearedifferenttypes

ofpHmeterslikeinstantpHmeter,digital

pH

meter,electronic

digital

pHmeter,andpHindicators.In

instantpHmeter

onecanseetheresultsinstantly;theinstrumentalso

does

notrequireany

calibrationwithbuffer

solutions.DigitalpHmetersarehandyandaccurate

forpHmeasuringofwaste

water,chem

ical,andfoodandforsome

laboratory

applications.pHindicatorsarewidelyusedin

variousindustrial

applications,andalso

they

aretechnically

designed

tomeettheindustrial

requirem

ents

(continued)

13.1 Instruments 391

(continued)

Instrument

Feature

Image

WhileusingpHmetersdependinguponthetype,oneshould

becarefulon

thefollowingpoints:(a)stabilizationofsolutionisrequired

before

taking

reading,(b)betterto

keeptheelectrodes

deepin

buffer

of7.00pHsolution

when

notin

use,(c)thepHmeter

mustbecalibratedusingstandard

solutionbefore

unknownsolutionismeasured,and(d)temperature

ofthe

solutionalso

playsan

importantrole

inaccurate

measurementofpH

Lam

inar

flowsystem

Likew

iseto

that

ofmedical

andother

research

laboratories,agriculture

laboratories

also

requiresterileworkingenvironmentsin

order

tocarryout

specializedwork.Lam

inar

airflowscanmaintain

aworkingarea

free

from

contaminants.Lam

inar

flow

cabinetscreate

particle-free

working

environmentsbyprojectingairthroughafiltrationsystem

andexhaustingit

across

awork

surfacein

alaminar

orunidirectional

airstream

.They

providean

excellentcleanairenvironmentforanumber

oflaboratory

requirem

ents.Amongdifferenttypes

ofcabinetswithavariety

ofairflow

patternsfordifferentpurposes,theverticallaminar

flowcabinets,

horizontallaminar

flowcabinets,laminar

flowcabinetsandhoods,and

laminar

flow

benches

andboothsarewidelyused


BODincubator

Anincubatorisan

instrumentusedmostly

inbiological

studieswhichcan

maintainoptimaltemperature,humidity,andotherconditionsforgrowthof

microbiologicalorcellculture.BODincubatorisan

incubatordesigned

to

maintain

20� C

temperature

necessary

toperform

atestcalled

biochem

ical

oxygen

dem

and(BOD).Itinvolves

incubatingsamplessaturatedwith

oxygen

at20� C

temperature(usually)for5days.Thereareotherincubators

designed

tomaintaintemperaturesof5� C

ormoreaboveam

bienttoas

high

as100� C

tostudythegrowth

oforganismsofunder

temperateortropical

condition.Incubatorsdesigned

tomaintain

temperaturesbelowam

bientto

aslowas

about10� C

aregenerally

called

low-tem

perature

incubators

Orbital

shaking

incubator

Thisisaspecialtypeofincubatorusefulforlife

sciencesapplications,

ferm

entationstudies,agingtests,growth

studies,andbiological

cultures

under

variouscontrolled

temperature

conditions.Advancedshaking

mechanism

provides

quietshakingandprecise

speedcontrolwithdigital

display

(continued)


(continued)

Instrument

Feature

Image

Digitalcolonycounter

Digital

colonycounterisan

indispensable

benchtoptoolforthebusy

microbiologistdesigned

forquickandaccurate

countingofbacterial

and

mold

coloniesin

petridishes

orsimilar

experim

entalunits.Sim

ply

place

thepetridishontheilluminated

pad

andtouch

thedishwiththepen

provided

tomarkeach

colonyin

turn.Thiscausesacountto

beregistered

onthedigitaldisplayandaudibletoneconfirm

seach

countmade.Marking

thedishwiththepen

avoidsmissingcoloniesordouble

counting.The

digitalcountonthedisplaycanberesetmanually

anytimebypressingthe

resetkey

provided.Glare-freeilluminationisessential

foroptimum

viewingofcolonies

Rotary

shaking

machine

Forproper

mixingormakingofsolution,continuousshakingisnecessary.

Theshakingbecomes

difficultwhen

preparinganumber

ofsuch

solutions/

mixtures.Rotary

shakingmachineisthereto

helptheresearchers.

Continuousshakingatvariablespeedfrom10to250RPM

single/doubleor

3-tierplatform

unitisthefeature

ofthistypeofinstrument.Speedcanbe

adjusted

digitally.Rotary

swirlingagitationisusedextensivelyin

tissue

culture

work

andother

chem

icalmixingprocedures.D.C.motordrives

the

shaker

mechanism

throughmechanical

transm

issionwithv-beltdrive.

Minim

um

precautionarymeasuresshould

betaken

tomaintain

thespeed,

time,andproper

placementofthesamples


Flamephotometer

Reliable

andaccurate

concentrationofNa,K,Li,Ca,etc.,in

solutions

remainsim

portantin

clinical

andsoillaboratories,andflam

ephotometer

playsagreatrolein

thisdirection.Flamephotometry

(alsoknownas

flam

e

atomicem

issionspectrometry)isabranch

ofatomicspectroscopyinwhich

thespeciesexam

ined

inthespectrometer

arein

theform

ofatoms.The

other

twobranches

ofatomic

spectroscopyareatomic

absorption

spectrophotometry

(AAS)andinductivelycoupledplasm

a–atomic

emissionspectrometry

(ICP-A

ES),arelativelynew

andveryexpensive

technique.In

allcasestheatomsunder

investigationareexcitedbylight.

Flamephotometry

issimple

andrelativelyinexpensiveandusedfor

clinical,biological,andenvironmentalanalysis.Flamephotometry

is

suitable

forqualitativeandquantitativedeterminationofseveral

cations,

especiallyformetalsthat

areeasily

excitedto

higher

energylevels

(nam

ely,Na,K,Rb,Cs,Ca,Ba,Cu)atarelativelylowflam

etemperature.

Carefulandfrequentcalibrationisnecessary

forgoodresults,anditisvery

importantto

measure

theem

issionfrom

thestandardandunknown

solutionsunder

conditionsthat

areas

nearlyidenticalas

possible.The

processes

inaflam

ephotometer

includethefollowingstages:desolvation

(drying),vaporization,atomization,andionization.Eachofthesestages

includes

therisk

ofinterference

incase

thedegreeofphasetransfer

is

differentfortheanalyte

inthecalibrationstandardandin

thesample

Hotairoven

andhot

airsterilizer

Anelectrical

instrumentusedforsterilization.Theoven

usesdry

heat

50–300� C

(generally)tosterilizearticles.T

hesearewidelyusedtosterilize

articles

that

canwithstandhightemperaturesandnotget

burned,like

glasswareandpowders.Linen

getsburned

andsurgical

sharpslose

their

sharpness.Generally,adigitally

controlled

thermostat

maintainsthe

temperature.Double

walledinsulationseparated

byan

air-filled

spacein

betweenkeepstheheatin

andconserves

energy.Anaircirculatingfan

helpsin

uniform

distributionoftheheat.Thecapacitiesoftheseovens

vary.Power

supply

needsvaryfrom

countryto

country,dependingonthe

voltageandfrequency

(hertz)used.Tem

perature-sensitivetapes

orother

devices

likethose

usingbacterialsporescanbeusedto

work

ascontrols,to

testfortheefficacy

ofthedevicein

everycycle.They

donotrequirewater

andthereisnotmuch

pressure

buildupwithin

theoven,unlikean

autoclave,makingthem

saferto

work

with.Acomplete

cycleinvolves

heatingtheoven

totherequired

temperature,maintainingthattemperature

fortheproper

timeinterval

forthat

temperature,turningthemachineoff,

andcoolingthearticles

intheclosedoven

tillthey

reachroom

temperature

Ifthedoorisopened

before

time,heatescapes

andtheprocess

becomes

incomplete.Thus,thecyclemustbeproperly

repeatedallover

(continued)


(continued)

Instrument

Feature

Image

Autoclave

Anautoclaveisadeviceusedto

sterilizeequipmentandsupplies

by

subjectingthem

tohigh-pressure

saturatedsteam

at121� C

foraround

15–20min

dependingonthesize

oftheload

andthecontents.Thenam

e

comes

from

Greek

auto-,ultim

atelymeaningself,andLatin

clavis

meaningkey—

aself-lockingdevice.Autoclaves

arewidelyusedin

microbiology,medicine,tattooing,bodypiercing,veterinaryscience,

mycology,dentistry,chiropody,andprostheticsfabrication.They

varyin

size

andfunctiondependingonthemedia

tobesterilized.Typical

loads

includelaboratory

glassware,surgical

instruments,medical

waste,patient

pairutensils,andanim

alcagebedding.A

notable

growingapplicationof

autoclaves

isthepredisposaltreatm

entandsterilizationofwaste

material,

such

aspathogenic

hospital

waste.Machines

inthiscategory

largely

operateunder

thesameprinciplesas

conventional

autoclaves

inthat

they

areable

toneutralizepotentially

infectiousagentsbyutilizingpressurized

steam

andsuperheatedwater.Autoclaves

arealso

widelyusedto

cure

compositesandin

thevulcanizationofrubber.Thehighheatandpressure

thatautoclavecreatesallowto

ensure

thebestpossiblephysicalproperties

ofthematerialusedforsterilization

Whileusingthisinstrumentin

thelaboratory,care

mustbetaken

such

that

thepressure

andtemperature

donotcross

beyondthecapacityofthe

instrument;otherwise,thereiseverypossibilityofmeetingaccidents.

Maintenance

ofappropriatetime,temperature,andpressureisthekey

point

tobenotedforhighesteffectivity

Stovetopautoclaves—

thesimplestofautoclaves


Analyticalbalance

Analyticalbalance

isusedto

measure

massto

averyhighdegreeof

precisionandaccuracy.Themeasuringpan(s)ofahighprecision(0.1

mg

orbetter)analyticalbalance

isinsideatransparentenclosure

withdoorsso

asto

avoid

dustparticles

andairflow

inaffectingthebalance’s

operation.

Analyticalprecisionisachieved

bymaintainingaconstantload

onthe

balance

beam,bysubtractingmassonthesamesideofthebeam

towhich

thesample

isadded.

Precautionshould

betaken

toavoid

airflow

duringrecordingofweights

andunder

dust-freecondition

Compound

microscope

Microscopeisatoolusedtoviewsm

alltinyelem

ents,w

hicharemostlynot

clearlyvisiblebythenaked

eye.In

life

science,medicalscience,andother

branches,m

icroscopeisan

essentialinstrumentinresearch.Aslightfroma

sourcepassesthroughtheobject,thelensnearesttheobject,theobjective

lens,producesan

enlarged

imageoftheobjectin

theprimaryim

ageangle.

Thelensthatyoulookinto,theeyepiece,actsas

amagnifier

andproduces

anenlarged

imageoftheim

ageproducedbytheobjectivelens.The

magnificationistheproduct

oftheeyepiece

magnificationbythe

magnificationoftheobjectivelens,usually

4�,

10�,

40�,

and100�.

For

exam

ple,a

10�eyepiece

inconjunctionwitha40�objectivewillgiveyou

amagnificationfactorof400;thatmeanstheobjectwillbemagnified

400

times

larger

than

youcanview

itwiththenaked

eye.Viruses,molecules,

andatomsarebeyondthecapabilitiesoftoday’scompoundmicroscopes

andcanbeviewed

only

withan

electronmicroscope.Alwaysuse

immersionoilwhileviewinganyobject

using100�

eyepiece

toprevent

thedam

ageofthelens.Wipeoffthelensgentlywithtissuepapersoaked

in

xyleneto

removetheoilafteruse.Never

use

adry

cloth

orpaper

towelto

wipeanyopticalsurfaceas

youcould

scratchalens.Use

anairblower

ora

camel

hairbrush

towhiskaw

aydust.Ifthereisdirtontheeyepiece

that

can’tberemoved

withairorthebrush,gentlywipeitwithapiece

ofclean

cotton

(continued)


(continued)

Instrument

Feature

Image

Stereoscopic

microscope

Thestereo

ordissectingmicroscopeisan

opticalmicroscopevariant

designed

forlow-m

agnificationobservationofasample

usingincident

lightillumination.Itusestwoseparateopticalpathswithtwoobjectives

andtwoeyepiecesto

provideslightlydifferentviewinganglesto

theleft

andrighteyes.In

thisway

itproducesathree-dim

ensionalvisualizationof

thesamplebeingexam

ined.S

tereomicroscopyoverlapsmacrophotography

forrecordingandexam

iningsolidsampleswithcomplexsurface.The

stereo

microscopeshould

notbeconfusedwithacompoundmicroscope

equipped

withdouble

eyepiecesandabinoviewer.In

such

amicroscope,

both

eyes

seethesameim

age,butthebinoculareyepiecesprovidegreater

viewingcomfort.However,theim

agein

such

amicroscopeisnodifferent

from

that

obtained

withasingle

monoculareyepiece


Electronmicroscope

Anelectronmicroscopeisthemodernvariantofmicroscope.Ituses

abeam

ofelectronsto

illuminateaspecim

enandproduce

amagnified

image.Anelectronmicroscopehas

greater

resolvingpower

than

alight-

powered

opticalmicroscopebecause

electronshavewavelengthsabout

100,000times

shorter

than

visible

light(photons).Magnificationsofupto

about10,000,000�

canbeachieved

throughthesemicroscopes.Electron

microscopes

areusedto

observeawiderangeofbiological

andinorganic

specim

ensincludingmicroorganisms,cells,largemolecules,biopsy

samples,metals,andcrystals.Industrially,theelectronmicroscopeisoften

usedforqualitycontrolandfailure

analysis.Assuch

theseareusedin

all

types

ofresearch

activities.Electronmicroscopemay

be(1)transm

ission

microscope(TEM),(2)scanningelectronmicroscope,

(3)reflectionelectronmicroscope,(4)scanningtransm

issionelectron

microscope,and(5)low-voltageelectronmicroscope

(continued)


(continued)

Instrument

Feature

Image

Weather

station

Weather

param

etershavebecomeindispensible

partofmodernresearch,

particularlyin

thefieldoflife

science

andagriculture.Because

of

trem

endousdevelopmentassociated

withother

advantages,nowadays,

automaticweather

stations

(AWS)arepreferred

over

manual

weather

station.Measurementsonparam

eterscanalso

bemadefrom

remote

areas

throughtheuse

ofthesestations.Mostautomatic

weather

stationshave

thermometer

formeasuringtemperature,anem

ometer

formeasuringwind

speed,windvaneformeasuringwinddirection,hygrometer

formeasuring

humidity,andbarometer

formeasuringatmospheric

pressure.Someof

them

even

haveceilometer

formeasuringcloudheight,rain

gaugealong

withdatalogger,rechargeable

battery,andtelemetry,andthe

meteorological

sensors

withan

attached

solarpanel

orwindturbineare

mounteduponamast.Thespecificconfigurationmay

varydueto

the

purpose

ofthesystem

.Thesystem

may

reportin

nearreal

timevia

the

ArgosSystem

sandtheGlobalTelecommunicationSystem

orsavethedata

forlaterrecovery


Spectroscopy

Spectroanalyticalproceduresarenowadaysusedfordeterminationof

concentrationofelem

entsin

solutions.Atomic

absorptionspectroscopy

(AAS)isoneofsuch

quantitativeproceduresem

ployingtheabsorptionof

opticalradiation(light)byfree

atomsinthegaseousstate.AAScanbeused

todetermineover

70differentelem

entsin

solutionordirectlyin

solid

samples

Based

onBeer–Lam

bertlaw,itrequires

standardswithknownanalyte

contentto

establish

therelationbetweenthemeasuredabsorbance

andthe

analyte

concentration.Theprinciple

ofAASlies

onpromotingthe

electronsoftheatomsinto

higher

orbital

(excitedstate)

forafew

nanosecondsbyabsorbingadefined

quantity

ofenergy(i.e.,radiationofa

given

wavelength)whichisspecificto

aparticularelectrontransitionin

a

particularelem

entbecause,in

general,each

wavelength

correspondsto

only

oneelem

ent

(continued)


(continued)

Instrument

Feature

Image

PCRunit

Oneofthemajortoolsin

molecularbiologyisthePCR.Thepo

lymerase

chain

reaction

(PCR)unitisusedto

amplify

asingle

orafew

copiesofa

piece

ofDNAacross

severalordersofmagnitude,generatingthousandsto

millionsofcopiesofaparticularDNA

sequence.PCRisnow

acommon

andoften

indispensible

techniqueusedin

medical

andbiological

research

labsforDNAcloningforsequencing,diagnosisofhereditarydiseases,

identificationofgenetic

fingerprints(inforensicsciencesandpaternity

testing),detectionanddiagnosisofinfectiousdiseases,etc.Abasic

PCR

setuprequires

several

componentsandreagentslikeDNA

template,two

primers,Taq

polymerasedeoxynucleosidetriphosphates,buffer

solution,

divalentcations,andmonovalentcation.Theresearchersmustbecareful

because

PCRcanfailforvariousreasons,in

partdueto

itssensitivityto

contaminationcausingam

plificationofspuriousDNAproducts.According

tothevariationsonthebasicPCRtechnique,itcanbeallele-specificPCR,

asymmetricPCR,dial-outPCR,hotstartPCR,intersequence-specificPCR

(ISSR),inverse

PCR,ligation-m

ediatedPCR,methylation-specificPCR,

miniprimer

PCR,multiplexligation-dependentprobeam

plification

(MLPA),multiplexPCR,nestedPCR,overlapextensionPCR,splicingby

overlapextension(SOE),quantitativePCR(qPCR),reverse

transcription

PCR(RT-PCR),solidphasePCR,thermal

asymmetricinterlaced

PCR

(TAIL-PCR),touchdownPCR(step-downPCR),PAN-A

C,universalfast

walking,andin

silico

PCR(digital

PCR,virtual

PCR,electronic

PCR,e-

PCR)


Chromatography

Separationofconstituentsfrom

themixture

has

remained

themainfocal

pointin

chromatography.Chromatographyisthecollectionofasetof

laboratory

techniques.Therearetwophases—

themob

ileph

ase,which

carries,andthestationa

ryph

ase.Thevariousconstituentsofthemixture

travel

atdifferentspeeds,causingthem

toseparate.Chromatographymay

bepreparative(separatethecomponentsofamixture)oranalytical

(measuringtherelativeproportionsofanalytesin

amixture).

Chromatographymay

becategorizedby(a)chromatog

raph

icbedshap

e(columnchromatography,planar

chromatography,paper

chromatography,

thin-layer

chromatography)and(b)ph

ysical

stateof

mob

ileph

ase(gas

chromatography,liquid

chromatography,etc.)

HPLC

Oneoftheim

portantchromatographic

techniques

inanalyticalchem

istry

andbiochem

istryisthehigh-perform

ance

liquid

chromatography,also

knownas

high-pressure

liquid

chromatography(H

PLC),usedto

separatea

mixture

ofcompoundsforidentifying,quantifying,andpurifyingthe

individual

componentsofthemixture.HPLChas

manyusesin

medical,

purifyingsubstancesfrom

acomplexbiological

sample,manufacturing,

pharmaceutical,qualityassurance,etc.

(continued)


(continued)

Instrument

Feature

Image

Computer

Alandmarkin

thehistory

ofscience

istheinventionofcomputer.

Computerisan

electronicdevicethatisdesigned

towork

withinform

ation.

Theterm

“computer”

isderived

fromtheLatin

term

compu

tare;thismeans

tocalculate.Computercannotdoanythingwithoutaprogram.Computers

notonlyhelpincalculationbutalso

havebecomeintegratedcomponentsof

manymoderninstruments.Ageneral-purpose

computerhas

fourmain

components:thearithmeticlogicunit(A

LU),thecontrolunit,themem

ory,

andtheinputandoutputdevices

(collectivelyterm

edI/O).Thesepartsare

interconnectedbybusses,often

madeofgroupsofwires.Insideeach

of

thesepartsarethousandsto

trillionsofsm

allelectrical

circuitswhichcan

beturned

offoronbymeansofan

electronic

switch.Thecircuitsare

arranged

inlogic

gates

sothat

oneormore

ofthecircuitsmay

controlthe

stateofoneormore

oftheother

circuits.Thecontrolunit,ALU,registers,

andbasic

I/O(andoften

other

hardwareclosely

linked

withthese)

are

collectivelyknownas

acentral

processingunit(CPU).Aperiph

eral

isa

deviceconnectedtoahostcomputer,butnotpartofit.Itexpandsthehost’s

capabilitiesbutdoes

notform

partofthecore

computerarchitecture.Itis

often,butnotalways,partially

orcompletely

dependentonthehost

Computerandperipheral


13.2 Laboratory Safety Measures

Safety measures can broadly be categorized into

two groups—the human safety and the instru-

mental or laboratory safety. Almost all labora-

tory equipments are sensitive and can become

dangerous if safety precautions are not taken

properly. Many equipments are something that

one can’t just drag around and store anywhere

because most equipments have their conditions

and specifications in installing, use, and storing.

Most of the instruments achieve high levels of

performance due to carefully designed interface

between external connectors and internal

components. As a result, specific handling

precautions must be observed for device reliabil-

ity and optimum performance. An appropriate

safety precaution to use with a laboratory instru-

ment depends on the type of instrument and

analysis to be carried out. For example, if one is

going to use an instrument having furnace, then

one is required to be careful about fire,

overheating, burning, etc. On the other hand, if

the instrument uses compressed gas, one needs to

be aware of how to make and maintain tight

connections to the gas source and may need to

look at adequacy of ventilation. While using the

instrument, one should be careful about the fol-

lowing points, though these are not exhaustive:

1. The equipment should be placed away from

heat sources. Do not block airflow around

equipment. If equipment be operated at high

ambient temperatures, mount with a good

thermal connection to a large thermal mass.

2. Do not allow foreign material into the enclo-

sure. Do not allow contamination to be

introduced into the connectors.

3. If applicable, always use the provided AC

adaptor. Do not power the unit with a different

adaptor. Do not modify the power plug or wall

outlet to remove the third (ground) pin.

4. Do not drop or shake the equipment. Mini-

mize vibration and handle with care.

5. Make sure to read the instructions in the lab

equipment and do not do experiments on

your own.

6. If you don’t know how to use the lab equip-

ment, it’s better to ask the expert to avoid

mistakes caused by hunches.

13.2.1 Precautionary Measures

Given below are some of the precautionary

measures one should follow while using the

instruments:

1. Autoclaves, heat sterilizers, and pressure

cookers should be run only by experts or

professionals. In using a pressure cooker,

check the safety valve before pressure is

built up. The equipment should be turned off

and allowed to cool before the stopcock is

opened to equalize pressure.

2. Incubators may be useful components of a

biology laboratory; care should be taken to

keep incubators safe and well maintained.

Unwanted growth of organisms should be

restricted by regular cleaning.

3. Microscope: if it has a cover or case, alwaysput it in place when you aren’t using the

device. Wet or dirty slides should never

be put on the stage, which should always be

kept dry. When cleaning your microscope,

unplug it first, if applicable, and then clean

the outside using a damp, soft cloth only.

Never use a dry cloth or paper towel to

wipe any optical surface as it could scratch

lens. Use an air blower or a camel hair brush

to whisk away dust. If there is dirt on the

eyepiece that can’t be removed with air or

the brush, gently wipe it with a piece of clean

cotton.

4. Chromatography

(a) Dissolving and developing solvents give

off toxic vapors. They must be stored in

closed containers and the room should

properly be ventilated.

(b) Solvents are highly flammable and must

not be used near an open flame.

(c) Avoid skin contact when spraying the

developing solvents.

(d) Use a fume hood when appropriate.

13.2 Laboratory Safety Measures 405

5. Biotechnology

(a) Handle all microorganisms and DNA

carefully. Treat them as if they could

cause infections.

(b) Hands should be washed with soap and

water before and after handling micro-

organisms and before leaving the labora-

tory regardless of what materials were

used. When handling microorganisms or

other living materials, wear rubber gloves

to protect against infection.

(c) Use only mechanical pipetting devices for

transferring any material. Do not allow

mouth pipetting.

6. Greenhouse maintenance and operation

(a) Check waterlines, heating system, fans,

and temperature control. These are usu-

ally routine procedures but must be done

every time.

(b) Make sure all automatic equipments are

functional and accurate.

(c) Clean tools after use and store them

appropriately.

13.2.2 Human Safety Measures

(a) Use safety equipment in performing tests and

experiments such as safety goggles to avoid

anything from entering your eyes, which could

be anything from chemicals to shrapnel.

(b) Don’t eat or drink in the laboratory or near

lab equipment that has chemicals or sample

in them. While you may want to feel

refreshed and relaxed in the lab, it’s not

worth to risk in case you swallow something

by mistake.

(c) Many people are allergic to pollen, mold

spores, or other plant exudates. When using

flowers, mushrooms, fungi, etc., in the labo-

ratory, adequate ventilation is essential. Pol-

len and mold spores should be displayed in

closed glass petri dishes.

(d) Do not apply cosmetics in the laboratory.

Keep fingers and writing instruments away

from your face and mouth.

13.2.3 Overall Laboratory Condition

(a) Keep the laboratory clean.

(b) Disinfect the work area before and after each

laboratory procedure. Use of a commercial

disinfectant to wipe down the area is

acceptable.

(c) While working the researcher should use

gloves, chemical splash safety goggles, and

aprons as would be found necessary.

(d) Containers should be cleaned before and

after use.

(e) Do not leave laboratory materials unattended

or ill maintained. They should be cleaned out

regularly to prevent unwanted growth of

organisms.

(f) Laboratory should be well equipped with

proper lighting, adequate heat, and water sup-

ply along with fire extinguisher.

(g) Commercial potting mixtures are

recommended over garden soil because they

are relatively sterile.

13.3 Computer, Computer Software,and Research

By this time, the importance of statistics to a

researcher is clear. Statistics are best used when

it is supported by strong computing facilities.

The need for developing computing facility was

felt time and again. Many of the statistical tools

would not have been used at a large scale if there

was no effective development in the computing

facilities. Development of computers and statis-

tical software has made it possible to have wider

application of statistics in unearthing and/or

explaining the so long hidden truth of this uni-

verse. But this development is not unidirectional

or flawless. For best application, understanding

the theories and situations where actually the

specific statistical tools are required to be used

is essential. Statistical theories are used best by

the subject matter specialists in consultation with

an efficient statistician. Understanding of both

the specialists towards the field of each other to

a certain degree is essential for efficient use of


statistical theories towards advancement of

human civilization. Statistics is just like a

molded clay; one can make God or devil out of

it as per the choice of the user. Unfortunately, in

many of the cases, statistical calculations have

been made with the help of the computer

packages, without knowing the logic and

utilities. Misuse of statistical concept is increas-

ing day by day. We must be cautious about

garbage in, garbage out (GIGO). The researcher

must have a clear idea about what are the

requirements, what are inputted to the computer,

and what are the commands to be given to the

computers to get the required information

analyzed properly befitting to the requirement

of the objectives of the research program.

A computer does not have any brain; the only

thing it can do is the use of stored program as per

the direction of the user. Using a set of data, one

can get innumerable types of output just by

changing instruction to the computer. But defi-

nitely all of these outputs are neither relevant nor

correct under the given situation. For best use of

the computer, it is feasible to get from the infor-

mation fed to the computer using statistical

theories, what should be the direction to the

computer and what is the output generated by

the computer. In the following example, we

shall demonstrate how many types of statistical

analysis could be taken up. While using statisti-

cal software, the following points are required to

be noted:

1. The background information about the data

2. Nature of the data

3. Objectives of the experiment

4. Hypothesis to be tested

5. Appropriate statistics to be calculated for 3

and 4 using the specific type of data

6. Background knowledge about the statistical

package to be used w.r.t. its algorithm,

techniques used in performing the task

7. Testing the accuracy of the software using

solved identical example

8. Knowledge about the explanation of the out-

put after running the statistical package and

linking these with the objective of the study

Example 13.1 The following table gives yield

(q/ha) of a particular paddy variety. The experi-

ment was conducted with three types of manure

and three doses of nitrogen to standardize the

supplement of inorganic nitrogen by manure,

and the experiment was conducted under field

condition for two consecutive seasons. The prob-

lem is to find out the best dose of nitrogen and

best manure to get the best yield.

Before analyzing the data information on the

type design followed is a must. But most fre-

quently it is found that after completion of the

experiment, the researcher searches for appropri-

ate method of data analysis. Actually in designs

of experiments, once the experimental design is

fixed, its analysis is also fixed. In the absence of

full information, the above data could be

analyzed in various forms, and the results of all

these analyses are not identical. Here, some of

the possible analyses along with experimental

design assumed in each stage are provided.

Readers may note that these are not exhaustive;

one can have other types of analysis with the

same data. We have presented the ANOVA

tables only, from which it is clear that there

exist differences among the analyses and as

such the interpretation will also vary. Thus,

appropriate analysis of the data is required to

extract the information. Otherwise, misleading

Nitrogen N1 N1 N1 N2 N2 N2 N3 N3 N3

Rep R1 R2 R3 R1 R2 R3 R1 R2 R3

Manure 1 Season 1 57.80 65.06 67.78 68.77 70.37 76.47 76.07 64.67 75.37Season 2 58.43 65.69 68.41 71.37 61.01 68.07 68.81 69.31 70.10



13.3 Computer, Computer Software, and Research 407

conclusion may be drawn. In fact in statistical

software, there are a varied range of options

for execution of analysis; one must be sure

about the exact procedure to be adopted for

that knowledge on analytical tools and the

specifications/command of the statistical software

are essential (Tables 13.1, 13.2, 13.3, 13.4, 13.5,

and 13.6).

Table 13.2 Analysis of data using randomized complete block design for season, with manure and nitrogen as split

plots on season

Analysis of variancetable

K value Source Degrees of freedom Sum of squares Mean square F-value Prob

1 Replication 2 25.020 12.510 1.4902 0.4016

2 Season 1 36.787 36.787 4.3822 0.1714

�3 Error 2 16.789 8.395

4 Manure 2 351.847 175.923 6.4008 0.0046

6 SM 2 28.528 14.264 0.5190

8 Nitrogen 2 53.707 26.853 0.9770

10 SN 2 32.885 16.442 0.5982

12 MN 4 454.189 113.547 4.1313 0.0082

14 SMN 4 190.808 47.702 1.7356 0.1665

�15 Error 32 879.507 27.485

Total 53 2070.066

Table 13.1 Analysis of data using three-factor randomized complete block design



1 Replication 2 25.020 12.510 0.4745

2 Season 1 36.787 36.787 1.3955 0.2457

4 Manure 2 351.847 175.923 6.6735 0.0036

6 SM 2 28.528 14.264 0.5411

8 Nitrogen 2 53.707 26.853 1.0187 0.3718

10 SN 2 32.885 16.442 0.6237

12 MN 4 454.189 113.547 4.3073 0.0063

14 SMN 4 190.808 47.702 1.8095 0.1498

�15 Error 34 896.296 26.362

Total 53 2070.066

Table 13.3 Analysis of data using randomized complete block design for season and manure with nitrogen as a split

plot on season and manure



1 Replication 2 25.020 12.510 0.5800

2 Season 1 36.787 36.787 1.7055 0.2208

4 Manure 2 351.847 175.923 8.1563 0.0079

6 SM 2 28.528 14.264 0.6613

�7 Error 10 215.691 21.569

8 Nitrogen 2 53.707 26.853 0.9469

10 SN 2 32.885 16.442 0.5798

12 MN 4 454.189 113.547 4.0040 0.0126

14 SMN 4 190.808 47.702 1.6821 0.1869

�15 Error 24 680.605 28.359

Total 53 2070.066


Table 13.4 Analysis of data using randomized complete block design for season, with manure as a split plot on season

and nitrogen as a split plot on manure



1 Replication 2 25.020 12.510 1.4902 0.4016

2 Season 1 36.787 36.787 4.3822 0.1714

�3 Error 2 16.789 8.395

4 Manure 2 351.847 175.923 7.0758 0.0170

6 SM 2 28.528 14.264 0.5737

�7 Error 8 198.902 24.863

8 Nitrogen 2 53.707 26.853 0.9469

10 SN 2 32.885 16.442 0.5798

12 MN 4 454.189 113.547 4.0040 0.0126

14 SMN 4 190.808 47.702 1.6821 0.1869

�15 Error 24 680.605 28.359

Total 53 2070.066

Table 13.5 Analysis of data using two-factor randomized complete block design combined over seasons



1 Season 1 36.787 36.787 1.3384 0.2559

3 R(S) 4 41.809 10.452 0.3803

4 Manure 2 351.847 175.923 6.4008 0.0046

5 SM 2 28.528 14.264 0.5190

8 Nitrogen 2 53.707 26.853 0.9770

9 SM 2 32.885 16.442 0.5982

12 MN 4 454.189 113.547 4.1313 0.0082

13 SMN 4 190.808 47.702 1.7356 0.1665

�15 Error 32 879.507 27.485

Total 53 2070.066

Table 13.6 Analysis of data using two-factor randomized complete block design with split plot combined over

seasons



1 Season 1 36.787 36.787 1.4796 0.2585

3 R(S) 4 41.809 10.452 0.4204

4 Manure 2 351.847 175.923 7.0758 0.0170

5 SM 2 28.528 14.264 0.5737

�7 Error 8 198.902 24.863

8 Nitrogen 2 53.707 26.853 0.9469

9 SN 2 32.885 16.442 0.5798

12 MN 4 454.189 113.547 4.0040 0.0126

13 SMN 4 190.808 47.702 1.6821 0.1869

�15 Error 24 680.605 28.359

Total 53 2070.066

13.3 Computer, Computer Software, and Research 409

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