This new pro uctis ideally suited to G QSNmeasure L-ornithine Odecarboxylase, the initialenzyme in polyamine biosyn-thesis.(0) The enzyme activity is pyri-doxal-5'-phosphate dependent, and canbe used as a measurement of vitamin B6levels in a variety of tissues and body fluids.(2)
1. Russell, D.H., and S. Snyder, PNAS, 60,1420 (1968).2. Harris, R.S., in The Vitamnins, 2, W.H. Sebrell, Ed., Academic Press,New York, 1-116 (1968).
Ornithine, L-[1 -14C]- 40-60mCi/mmol0.01 N HCI solution.NEC-710 $54/10,aCi $140/50ACi
Nerw England Nuclear549 Albany Street, Boston, Massachusetts 02118CustomerService 617-482-9595
NEN Canada Ltd., Lachine, Quebec, NEN Chemicals GmbH, Dreieich, W. Germany.Circle No. 129 on Readers' Service Card
Prefilled, disposable, miniaturized chromato-graphic columns and reagent solutions, ready-to-use for clinical testing.Also, a broad array of inexpensive empty glassand plastic columns, and column fittings, is avail-able for your own use in developing new micro-chromatographic separation methods.
For further informationwrite orphone:216-825-4528800-321-9632 (toll-free)
IISOL Bin.r s INNOVATIVE
BIOCHEMICALMETHODOLOGY
Drawer 4350 Akron Ohio USA 44321
Three new reasons why your department should
ASHINO1. New End-of-Ashing Detector.We've incorporated an opticalfeedback mechanism that usesspectral analysis to determine ifany ashing is going on. If thesample is entirely ashed, orneeds stirring, your IPC systemwill let you know.
2. New Temperature Control.Transferring technology wedeveloped in maintaining acritical temperature envelopefor semiconductor manufac-turing, we have built asophisticated temperature probeinto our ashing chamber forreal-time control overtemperature at the sample.
3. New Heat Lamps. Until now,the only benefit you derivedfrom plasma ashing was its speedat low temperatures. Now youcan enjoy plasma's cleanliness,safety and inexpensiveunattended operation and get ridof your expensive and hazardousperchloric acid. These are
important advantages when youneed speed and are ashing a lotof samples. Now you can dohigh temperature ashing simplywith our efficient new built-inheat lamps.So: Three good new reasons.And there are many more thatwon't fit this space. Please letus tell you our complete storyand show what other chemistsand spectroscopists are doing inthe QC Laboratory with ourashers ... Analyzing plastics,paints, foods, drugs and more.Call or write Dick Bersin; ask forIPC Bulletin 4802.
International Plasma Corpora-tion, 31159 San Benito Street,Box 4136, Hayward, CA 94544.(415) 489-3030.
CircleINo211 -' //- ' , SCIENCE, VOL. 195
Circle No. 230 on Readers' Service Card
Circle No. 211 on Readers'Service Card806
Thejob nobody wants. Yet ifyou don't keep your still me-ticulously clean, your water quality goes downhill- andit may not be high enough now!But why put up with the doubt and aggravation when you
can have consistently better water at lower cost- withvirtually no maintenance?Water from a Milli-QT system exceeds all standards for
reagent grade purity. Maintenance?Just change adisposable cartridge.You could keep your still for feedwater to the Milli-Q. But
our Milli-RO' reverse osmosis system is a more economi-cal source- and it's virtually maintenance free.For consistent (and higher) water quality, far less main -
tenance, and lower cost per liter, a Milli-Q/ Milli-RO com -bination makes much more sense than a still.
Call us toll free at 800-225-1380 for a free copy ofourbulletin on high purity water systems.(In Canada 800-261-0961; in Mass. 617-275-9200).Millipore Corporation, Bedford, Mass. 01730.
I -
Milli-RO system Milli-Q system
MILUe 2 o e sr=Circle No. 225 on Readers' Service Card
InstantFluorescence...Just add theAO Vertical IlluminatorF---^---------______ 1
4Now you can extend the versatility of your AO'MICROSTAR® Microscope with the simple ad-dition of the new compact Vertical Illuminatorfor incident light fluorescence microscopy. Itfits any Series 1 0 or20 MICROSTAR Microscope;attaches easily and quickly; requires no ad-ditional alignment or adjustment.Preselected barrier, exciter and dichroic filtercombinations are mounted on individual, inter-changeable Fluor Clusters which are fitted ateach end of a slideway. A single lever positionsthe desired filter combination. There are no dialsto rotate or loose filters to handle. Selection issimple, accurate, and fast.A third position on the slide is open for trans-mitted brightfield. Switch from one to the otherwith ease.Choice of 100W Tungsten Halogen or 50WMercury Vapor light source. Both produce max-imum fluorescence intensity regardless ofspecimen's thickness or density.Fluorescence has never been easier. See yourAO Dealer or representative for a demonstra-tion on your AO Series 10 or 20 MICROSTARMicroscope ... or ours. In the meantime-sendfor detailed brochure. American Optical, Scien-tific Instrument Division, Buffalo, N.Y. 14215. Circle No. 188 on Readers' Service Card
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AmericanOptical