Exclusive'

FMromTekmar.SDT Series TissumizerOThe SDT Series TissumizerO ,a hand-held or stand-mountedhomogenizer, features inter-changeable rotor-stator generatorsfor varied volumes and liquidmedia. There are generators tohandle sample volumes from 5 to500 ml and from 1 to 10 ml;Microprobe processes samplevolumes from 0.3 to 5.0 ml. TheTissumizerl disintegrates tissues,cells, bacteria; homogenizessoils, air pollutionfilters, etc.Circle No. 347

New Tissuminceraccessory for SD-

Homogenizer. For tmincing and slicir

of tissue.Circle No.202

PETRIPERM@

PETRIPERM® culture dishes feature a 25-micronthick gas permeable plastic membrane instead ofthe conventional culture surface. Both hydrophobicand hydrophilic types allow carbon dioxide, oxygen,nitrogen or other gas to pass through from belowto the growing cells. This method opens new hori-zons in cell culture by better control of thegrowth environment.Circle No.352

"Stomachers " Lab Blender

A unique method of blending samples whichgreatly minimizes chance of contamination, ofeither sample or chamber. Sterile conditionscan be maintained. Sample and diluent are

7 placed in a plastic bag. Two reciprocatingpaddles apply controlled pressure. Entireprocedure takes about 30 sec. Four modelswith volumes from 5 to 3500 ml.Circle No.351

the

HeraeusC02/02 Incubator

Heraeus' C02/02 incubators offer manysophisticated extras for demanding researchapplications. They provide precise control ofimportant variables- C02/02, temperature,pH and humidity. All controls are activeand continuous. A stainless steel interior isstandard, with optional copper interior toinhibit contamination. Special accessoriesfor handling various culture vesselsare available.Circle No. 353

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Vega Icustom DJust a year ago, finding a source forcustom polynucleotide synthesis waslike trying to change lead into gold.Now, we can not only give you thecustom polynucleotides you need.but we can supply them quicklyand at excellent prices. Vega is thereliable source of custom productsyou've been looking for to speedyour genetic research.

Vega produces custom polynu-cleotides by solid phase techniquesusing Vega-manufactured reagentsand the Vega Polynucleotide Synthe-

but of thesizer. Because we perform syntheseswith our equipment, Vega offers thebest delivery and prices available. Weschedule the custom synthesis uponreceipt of your order, and give you afirm delivery date. You receivea fully purified and sequencedpolynucleotide that meets our rigidstandards for quality assurance. Callus toll free at 1-800-528-4882 for aquotation on any length of nucleotideup to an entire gene.

Circle No. 189 on Readers' Service Card

itnarx ages.To receive a free poster of theabove illustration, just send us yourname and address.

vega biochemicalsDivision of Vega Biotechnologies, Inc.Post Office Box 11648Tucson, Arizona 85734Telephone: (602) 746-1401Telex: 165572 (VEGA BIO TUC)

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NEW ENGLANDSYNTHETIC DNA ,OLIGOMERS FromNew England Biolabs now has available defined sequence oligonucleotides at lowcost to the scientific community.Our current products are listed below. All are tested to meet rigorous standards.For example, each linker or adapter is labelled with 32P and ligated with T4 DNAligase. The ligation mixture is recut with the appropriate restriction enzyme. Theseresults are included with each product.

PRIMERS I CUSTOM SYNTHESISM13 Sequencing Primer We offer a custom synthesis service

d(TCCCAGTCACGACGT) where defirled oligodeoxyribo-M13 Reverse Sequencing Primer nucleotides can be made to your

d(AACAGCTATGACCATG) specificationM1 Hybridizatio|PrbePrime Please call us at (617) 927-8576 tod(CACAATTCCACACAAC)dicsyorne.

pBR322BamH-I Site Primer- (CCACTATCGACTAC) Send for our latest catalog.

LIN-KERSBaMHI Hind Ill Sac I

d(CGGGATCCCG) d(CAAGCTTG) d(CGAGCTCG)Bcl I Kpn I Sal I

d(CTGATCAG) d(TGGTACCA) d(GGTCGACC)Bgl 11 Pst I Sma I

d(CAGATCTG) d(GCTGCAGC) d(CCCGGG)

C/a I Pvu I Xba Id(CATCGATG) d(CCGATCGG) d(CTCTAGAG)

EcoRlR Pvu 11 Xho Id(CGGAATTCCG) d(CCAGCTGG) d(CCTCGAGG)

ADAPTER 5 * Sma I Linker must be ordered separately.BamHI Hind III EcoRI Sal IGATCCCCGGG AGCTCCCGGG AATTCCCGGG TCGACCCGGG

GGGCCC* GGGCCC* GGGCCC* GGGCCC*

low GLANDORGANIC SYNTHESIS DIVISION (61 7) 927-8578283 CABOT ST., BEVERLY, MASSACHUSETTS 01915. U.S.A.New England Biolabs GmbH * Postfach 2750 * 6231 Schwalbach/TS. * West Germany (06196) 3031

Circe No. 419 on Readers' Service Car

I

I1188 SCIENCE, VOL. 215

Napco® promises you:

No other waterjacketed

C02 incubator can match the

new 6000 series.

Over 15 advancedfeatures are makingincubator history.Here are a fewof them.More accuratecontrol ofchambertemperature.By positioning sensors notonly in the water jacket,but in each separatechamber, Napco permitsmore precise chambermonitoring than otherwater jacketed-incubators.

The only waterjacketed C02incubator you can get

really clean.Shelfstandards andplenums canbe easilyremoved for

cleaning in fiveminutes. This leavesan empty, perfectlysmooth chamber thatcan be swabbed foreasy management ofspores andcontaminatingorganisms.

If you should ever have an equipment breakdown. ..A Henicke/NapcoMinute Man will be on his way to you in 48 hours. You'll seldom needthe Minute Man service, because Heinicke and Napco instruments arebuilt to work. But if you do, dial toll-free 800-327-9783.

Unique wet-jetair flow system.The exclusive wet-jet airflow system providesmaximum chamberuniformity and assures thehighest relative humidityavailable in any incubator.

And the list goes on.Feature afterfeature aredesigned for yourconvemence andprecision perform-ance. Send for the

completebrochure.All Napcowater-jacketedincubatorsare availablein threespace-savingmodels.

HEINICKEnapcoNational Appliance CompanyHeinicke Instruments Company3000 Taft Street, Hollywood, Fl. 33021800-327-9783 or (305) 987-6101Telex: 512610Circle No. 230 on Readers' Service Card

Ask your dealer's salesman today.Curtin-Matheson, Fisher Scientific Co.,Preiser, Sargent-Welch, S.G.A.Scientific, Scientific Products, Arthur H.Thomas Co., In Canada: Canlab, FisherScientific Co., Ltd., Sargent-Welch ofCanada Ltd.