T20 TOCOPRODUCTS & Pvt. Ltd

A COMPANY SERVE FOR STUDENTS

T20 EXAM PATTERN

PROUDLY INTRODUCING

BY T20 TOCO PRODUCTS & Ltd.

IN ASSOCIATION WITH

THE TAMILNADU DR. MGR MEDICAL

UNIVERSITY

REDUCING THE EXAM TIME BY

ONE HOUR

AND

MARKS BY 50

INTR

ODUCE BREAK

AFTER E

ACH 30

MINUTE

S

GIVE FREE HIT MARKS

FOR EVERY

UNEXPECTED QUESTIONS

FIRST 30 mins. POWER PLAY

NO SUPERVISOR

IN THE HALL

CHEER GIRLS IN EVERY CLASS.

THEY WILL DANCE AFTER FININSHING

EVERY PAGE

COUNTING COUNTING OF OF

BACTERIABACTERIA

BACTERIAL COUNTBACTERIAL COUNT

COUNT OF LIVING AND DEAD CELLS COUNT OF LIVING AND DEAD CELLS

TOTAL COUNT.TOTAL COUNT.

COUNT OF ONLY LIVING OR VIABLE CELLSCOUNT OF ONLY LIVING OR VIABLE CELLS

VIABLE COUNT.VIABLE COUNT.

TOTAL COUNT TOTAL COUNT METHODSMETHODS

Direct methods:Direct methods:

Breed’s methodBreed’s method

Wright’s method Wright’s method

Counting ChamberCounting Chamber

Coulter counter methodCoulter counter method

Membrane filtration Membrane filtration

Total count Total count methodsmethods

Indirect methods:Indirect methods:Visual methodVisual method

Photometric methodPhotometric method

ColorimetryColorimetry

NephlometryNephlometry

Packed cell volumePacked cell volume

Dry weightDry weight

VIABLE COUNTVIABLE COUNTSOLID MEDIA TECHNIQUESOLID MEDIA TECHNIQUE

Pour plate methodPour plate method

Surface viable methodSurface viable method

Drop techniqueDrop technique

Spreading techinqueSpreading techinque

VIABLE COUNTVIABLE COUNT

ROLL TUBE METHODROLL TUBE METHOD

MEMBRANE FILTERATIONMEMBRANE FILTERATION

FLUID MEDIA TECHNIQUEFLUID MEDIA TECHNIQUE

COUNTING ANEAROBESCOUNTING ANEAROBES

TOTAL COUNT – BREED’S TOTAL COUNT – BREED’S METHODMETHOD

Microscopic slide – mark 01 Microscopic slide – mark 01

sq.mm areasq.mm area

Place stage micrometer in the Place stage micrometer in the

eye pieceeye piece

Dilute the suspension – spread Dilute the suspension – spread

carefully on the sq.mm area of carefully on the sq.mm area of

the slide – dry it – fix it – stained the slide – dry it – fix it – stained

– counted at the squares.– counted at the squares.

DO YOU KNOW DO YOU KNOW THESE?THESE?

SIZE OF SQUARE IN THE SIZE OF SQUARE IN THE EYEPIECEEYEPIECE AREA OF FLIM ON THE SLIDEAREA OF FLIM ON THE SLIDE

VOLUME OF SUSPENSION TAKEN on VOLUME OF SUSPENSION TAKEN on

the slidethe slide If you know ……………….If you know ……………….

THEN THE NUMBER OF ORGANISMS IN THEN THE NUMBER OF ORGANISMS IN

THE ORIGINAL SUSPENSION CAN BE THE ORIGINAL SUSPENSION CAN BE

CALCULATED.CALCULATED.

WRIGHT’S WRIGHT’S METHODMETHOD

Equal volumes of suspension and Equal volumes of suspension and

blood is intimately mixed.blood is intimately mixed.

Made a smear on the slide.Made a smear on the slide.

Fixed – stained – countedFixed – stained – counted

Number of bacteria and red cells Number of bacteria and red cells

are counted for 40 fields. are counted for 40 fields.

Number of RBC - 5X10Number of RBC - 5X106 6 perper cmcm22

As the ratio of blood As the ratio of blood cells to bacteria on cells to bacteria on the slide is known, the slide is known,

the number of the number of bacteria per cmbacteria per cm33 in in the suspension can the suspension can

be found by be found by proportionality.proportionality.

COUNTING COUNTING CHAMBERCHAMBER

Slide with recessed area that is Slide with recessed area that is ruled in squares.ruled in squares.

Drop of culture is placed over that Drop of culture is placed over that and place a cover slip. and place a cover slip.

Don’t allow any air to entrapDon’t allow any air to entrapAllow to settle the cells on the areaAllow to settle the cells on the areaView under phase contrast View under phase contrast

microscopemicroscopeStain and focus under normal Stain and focus under normal

micros.micros.

Number of organisms in 04 Number of organisms in 04 groups of 16 small squares are groups of 16 small squares are countedcounted

CIRCULAR DITCH CELL STRAIGHT DITCHES

Cover glass

Ditches

Grid

Depressed cellSuspension celEnd view

COULTER COUNTER COULTER COUNTER METHODMETHOD

Flow of suspension

Tube

Electrode

Electrode

Orifice

Suspension

MEMBRANE MEMBRANE FILTRATIONFILTRATION

Provided that the suspension could be Provided that the suspension could be

sufficiently dilutedsufficiently diluted

Organism retained on the filter are stained – Organism retained on the filter are stained –

dried – counted under microscopedried – counted under microscope

The number of bacteria on the filter paper, The number of bacteria on the filter paper,

from a known volume of suspension can be from a known volume of suspension can be

calculatedcalculatedMostly applicable when the numb of organism is very small .

INDIRECT METHODSINDIRECT METHODS

COMPARISION WITH STANDARD

SUSPENSION

Use of std. opacity tubes.Use of std. opacity tubes.

10 tubes – solid suspn. of unglazed 10 tubes – solid suspn. of unglazed

porcelain in increasing OD.porcelain in increasing OD.

They are standardized against accurately They are standardized against accurately

counted bacterial Suspension.counted bacterial Suspension.

Comparing the opacity with standards.Comparing the opacity with standards.

VISUAL METHODVISUAL METHOD

PHOTOMETRIC PHOTOMETRIC METHODMETHOD

CALORIMETRY CALORIMETRY

NO. OF CELLS

METER

REA

DIN

G

LIGHT SOURCE

SPECIAL FILTER

SHUTTER

OPTICAL CELL

PHOTO CELL

AMOUNT OF LIGHT ABSORBED BY THE SUSPENSION IS CALCULATED

NEPHLOMETRY NEPHLOMETRY

THE AMOUNT OF LIGHT

REFRACTED BY THE

PARTICLES IN THE

SUSPENSION IS

MEASURED

PACKED CELL PACKED CELL VOLUMEVOLUME

Suspension is centrifugedSuspension is centrifuged

Depth of sediment is measuredDepth of sediment is measured

Equivalent num. of cells is obtained Equivalent num. of cells is obtained

from a graph of cell numbers from a graph of cell numbers

against paced cell volumeagainst paced cell volume

DRY WEIGHTDRY WEIGHT

Centrifuged cells – washed, Centrifuged cells – washed,

dried – weigheddried – weighed

Weight can be related to number of cellWeight can be related to number of cell

VIABLE COUNT

ROLL TUBE METHOD

SOLIDIFIED AGAR MEDIA LAYER

COLONIES

The rubber closure should be loosened during incubation

MEMBARANE FILTRATION

MEMBRANE FILTER IMPREGNATED WITH MEDIUM

BY STEREOSPECIFIC MICROSCOPE AND SURFACE ILLUMINATOR –

COUNTING CAN BE DONE

USING A FILTER OF 47 TO 50 MM DIAMETER – UP TO 200 COLONIES CAN BE COUNTED

FLUID MEDIA TEECHNIQUE

1 – 10 te

st su

spensio

n dilu

tion in

seria

l – fi

nd the tu

rbid

ity –

with d

ilutio

n fact

or – co

unting is

done

THANK YOU

I ACKNOWLEDGE MY MISTAKES IF ANY Meet again