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Even better

Itogether.

LKB Instruments, Inc.12221 Parklawn DriveRockville, Md 20852Tel. 301-881 2510telex 230 89 682

Individually, LKB chromatography instru-ments provide outstanding reliability andconsistently accurate results.But together, they form total, integrated sys-tems that are unequalled in their ease ofuseand dependability. The LKB 2111 MultiRac®Fraction Collector is the core ofjust such asystem.LKB excelience in designThe LKB 2111-MultiRacg system combines theultra-reliable 2111 Fraction Collector with thenew MicroPerpex® peristaltic pump, 2210dual channel recorder and high sensitivity2138 Uvicord®S UV monitor in one compactpackage. This entire system takes up less than2 square feet of bench or cold room space. Yet,every instrument is easy to reach and adjust.

Integrated ease of operationWith the programmable 2111 MultiRac con-trolling the run, you're assured of accurate,no waste, no problem collections. And withprecise pump control offraction volumes,

automatic flow stopfunction during tubechanges and contin-uous display offlow

wimcs w rate on the MicroPer-pex pump, the systemneeds minimal interac-tion time with labora-tory personnel.

Versatile and reliableThis new LKB collector draws on years ofdesign experience and incorporates the mostadvanced circuitry. Becausethe MultiRac preciselyshifts the drop head, it COLLECTION MODEcan accommodate a TIME DROP EXT.large variety ofcollec-tion vessels. lEIlJThe sophisticated mi- 4 5 6croprocessor controllerofthe collector lets youselect time, drop or precise vol-ume modes, diverts void volumes to waste andcan be programmed to save tubes by collectingvalleys in large volumes, peaks in small.See it ali togetherAsk your LKB representative for more infor-mation on LKB complete chromatography sys-tems. See how they work even better together.

Circle No. 196 on Readers' Service Card

SCIENCE, VOL. 212284

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-

BREAKTHE GLASS HABIT

- Nalgene1 'i Labware

_

Ar~'

as t t glass.Nalgene® PMP Volu tric Flasks are

just as clear as glass. P P (polymethyl-pentene) constructiorn es them the clar- 'ity of glass without th eakability. V

That makesNal olumetric Flasks t _safer than glass to hen you drop >- v.,_itone, it boujnces iAthe leakproof scir e tohandlethanafr pe adt

Nalgene V tric 1 iejus.accurate a er glThey're calibrated Tht lyoanteed hmits of er r&rin lyWked. Unlike Nal Lb Is

non- , so theseflacetheamount of eas (TC=TD).Nothing is left on fla -_And because Nalgene Volumetric Flasks

last longer than glass, you reducereplacement costs.

Put Nalgene Labware to the test, andsee why so many laboratories are breakingthe glass habit. Send for our current GlassNalgene Labware catalog, featuring over Labware250 products for professional use. Write:Nalge Company, Division of SybronCorporation, Nalgene Labware Depart-ment, Box 365, Rochester, N.Y 14602.And unbreakable Nalgene Labwarelasts longer.

SYBRON NalgeCircle No. 73 on Readers' Service Card

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To. Nature 15 East 26th Street,New York, N.Y. 10010

Please send me a year of Nature at '/2 price, $86.50, plusmy free Directory of Biologicalsprefer to try Nature for 6 months. $50. F 3 months: $30

enclose my personal checkPlease bill my credit card account

Account No:I Visa I Master O Amer. Ex Exp Date

Name

Address

city State ZipOrders must include personal check or credit card data. Offer good in theU.S. and Canada and is subject to change without notice. In the U.K.,send personal check for £37.50. or credit card data. to- Nature,4 Little Essex St., London WC2R 3LF

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NIKON/

INSTRUMENTATIONNikon Optiphot microscopewith CF objectives.SIGNIFICANCENikon's revolutionary CFoptics virtually eliminate chro-matic aberration. Within thisseries, several high perform-ance objectives significantlyextend observation powers.SPECIFICSWhile all Nikon CF objectivesprovide a dramatic improve-ment in resolution, color ren-dition and contrast over theold compensation system, thefollowing lenses are excep-tional. The unique CF 2x planapochromat has excellentimage flatness for low powerphotography. The CF 40x planapochromat, N.A. 0.95, dry,produces exceptionally bright,high contrast images. Nikon'sCF 100x NCG plan apochro-mat is designed to work with-out a cover glass. Its sharpnessmust be seen to be believed.These remarkable optics

are matched to a microscopebody and illumination systemequal to their performance-the Nikon Optiphot. This to-tally new design is extremelystable. A standard 50 watt hal-ogen Koehler illumination sys-tem covers all magnificationswithout need for adjustmentand the full range of Nikonaccessories is available tomatch any assignment.

Extend your vision. Write:Nikon Visions, Nikon Inc.Instrument Division623 Stewart Avenue

NIKON HIGH PERFORMANCECF OPTICS. POSSIBLY THE FINESTEVER AVAILABLE.Rat testis photographed with Nikon CF 40x oil plar

Garden City, N.Y. 11530(516) 222-0200

NikonExtending Man's VisionCircle No. 123 on Readers' Service Card

()KELVINATORCHROMATOGRAPHY

Kelvinator has three ways to meet your cold room chro-matography needs: One, two and three door refrigerationunits, packed with features designed especially for chro-matography applications.

Every Kelvinator refrigeration unit is constructed with anextra-thick layer of Urethane foam insulation for energy sav-ing operation. Large tempered thermopane glass doors offerexcellent visibility, close quietly and have superior insulatingqualities.

Each cabinet comes equipped with a vapor proof duplexreceptacle mounted inside, access portholes for attachingoptional recorders and other equipment, heavy duty adjust-able shelves and brilliant fluorescent lighting. A wide selec-tion of optional accessories is also available.

V I

In addition to offering the finest convenience features,every chromatography cabinet shares in Kelvinator's longtradition of dependable service. An exclusive Five YearCompressor Warranty Program? and world wide factory rec-ommended service network assures customers of first rateservice when and where it's needed.

When your needs call for cold room chromatographyequipment, remember . . . Kelvinator means refrigeration.

*Details of the Kelvinator Five Year Compressor Warranty Program are availableby contacting Kelvinator Commercial Products, Manitowoc, Wisconsin.

Kelvinator Commercial Products621 Quay Street,Manitowoc, Wisconsin 54220TWX-910-260-3507, Ph 1-800-558-7627

ffg7 A Division of White Consolidated Industries, Inc.

QUALITY REFRIGERATION RDRTHE LABORATORYCircle No. 9 on Readers' Service Card

L0II

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17 APRIL 1981 289

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With

Brinkmonn

Homogenizer,gou canhomojuenize

under mlD

1.

.homogenizeanoerobicalig

withecrosscontal

tut st > 00 0:-iwinution. 0 : :f

When it comes to breaking down m contamination andand homogenizing virtually any type ing problems, even an

of tissue, small organs, bones, bench-top unitthat homo-muscle, cartilage, or even wthout admitting air.an entire mouse, the ider its unique method ofBrinkmann Homogenizer destruction, a combination

is in a class by itself. onic energy and mechani-Consider its power. A 600W ng action, based on the

motor develops up to 30,000 rpm H Frequency Principle.(1200Won PT-45 model, with up to sider the optional electronic

20,000 rpm) to assure complete homogeniz otrl unit, with its sensor thaof most samples within 30 to 60 seconds (other fyrnonitors the actual speed and keepsinstruments may require 15 minutes or more). It cntant, regardless of load.

Consider the wide choice of generators, all From any standpoint, nothing compares withmade entirely of stainless steel. It includes a a Brinkmann Homogenizer. For literature, writeMicroprobe Generator small enough to fit into a Brinkmann Instruments, Inc., Subsidlary ofstandard cuvette (for samples as small as 1 ml or Sybron Corporation, Cantiague Road, Westbury,less), Anaerobic Generators for aerosol-free N.Y. 1590 or call toll-free 800/645-3050. Inhomogenization, a Mechanical Seal Generator to Qanada: Brinkmann Instruments (Canada), Ltd.

Brsnkmonn Homogenizers0Z; : :From tissue to homogenate in 30 seconds!

SYBRON I BrinkmannI For Information circle No. 108 on Readers' Servic Card

For a demonstration circle No. 109 on Reader' Seric Card01