NEW PRODUCTS
Multiple SGOT Assays In the continuous record of Serum Glutamic Oxala-
. . . a t a full scale sensitivity of 0.100 O.D.
cetic Transaminase assays illustrated, the determin ations are followed from start to endpoint. This method, since it does not measure absorbance changes over a fixed time interval, eliminates errors caused by nonlinear enzyme-substrate interactions. True linearity of the slopes permits accurate assays of small quantities of GOT from 1-minute segments. Here, the rate of reaction under uniform conditions provides that a change in absorbance of one chart division per minute is equivalent to an enzyme level of 5 GOT Units/ml. An output linear with absorbance, high sensitivity to small changes in absorbance and the rapid and simul taneous handling of four samples make the Gilford 2000 Multiple Sample Absorbance Recorder suitable for any enzyme assay which can be coupled to a DPN-DPNH oxidation-reduction reaction—and to a Flow meters shown comes with parallel face calibrations in both liters and in cubic feet. Available with flow-con t r o l valves of either nylon or stain less steel, t h e meter has a range of capacity sizes. The smallest model measures 0.5 t o 2 liters per minute; t h e largest has a range f r o m 10 to 8 0 liters per minute. Gelman Instru ment Co., P. 0 . Box 1 4 4 8 , Ann Arbor, Mich. 4 8 1 0 6 . 409
wide additional range of enzyme kinetics. The same linearity over a 0.0 to 3.0 O.D. range, sensitivity and long term stability adapt this system to a variety of other spectrophotometric
techniques—including
column chromatography, density gradients and RNA-DNA thermal denaturation. Standard accessories
The Model 610B electrometer has 1 mv., 0.01 picoampere, 1014 ohm, and 10~12 coulomb full scale sensitivity. This instrument is a special type of d.c. vacuum tube voltmeter having all the features of a conventional vacuum tube voltmeter plus 1014 ohm input re sistance. The instrument offers 11 volt age ranges, 28 current ranges; 25 re sistance ranges, and 15 coulomb ranges. Applications include directly measur ing potentials of vacuum tube plates and grids, pH electrodes, piezo-electric crystals, capacitors, etc. As a picoammeter, the unit can measure mass spec trograph currents. Other uses are in gas chromatography and nuclear stud ies. Keithley Instruments, 12415 Eu clid Ave., Cleveland 6, Ohio. 410
Absorbance Recorder
"Π BIOLOGY
A N D
FOR
MEDICINE
SALES OFFICES IN PRINCIPAL CITIES THROUGHOUT THE U. S. A.
gilford
Don't Discard Your W
Monochromator. . . U P D A T E
Applicator
An inexpensive thin layer chromatog raphy applicator permits coatings of layers of 0.30-, 0.5-, and 1.0-mm. thick ness and 50 or 100 mm. in width. The device can be used with glass of any kind of a width of 2 inches or more. Gallard-Schlesinger Chemical Mfg. Corp., 580 Mineola Ave., Carle Place, L. Ι., Ν. Υ. 11514. 4Π
INSTRUMENT®
Circle No. 1G6 on Readers' Service Card
Thin L a y e r Chromatography
4
MINUTES
C o n v e n t i o n a l S p e c t r o p h o t o m e t r i c Mea s u r e m e n t s a r e also more a c c u r a t e a n d c o n v e n i e n t w i t h t h e G i l f o r d 2000. A b s o r b a n c e v a l u e s f r o m 0.000 t o 3.000 O.D, are p r e s e n t e d o n a n u m e r i c a l c o u n t e r , readable t o O.001 O.D. P u s h b u t t o n c o n trolled cuvette p o s i t i o n i n g precisely aligns sample cells. Sensitivity, shutter a n d d a r k c u r r e n t a d j u s t m e n t s are e l i m i n a t e d . S y s t e m is c o m p l e t e l y l i n e oper ated a n d extremely stable.
* " ! > · *
I N S T R U M E N T A T I O N
3 -
Chart Record Courtesy of: Dr. S. Raymond Gambino Director of Laboratories The Englewood Hospital Englewood, New Jersey
Gilford Instrument Laboratories Incorporated Oberlin, Ohio
Multiple Sample
2 Τ IMt
Request brochure and quotation.
The Gilford 2000 Electrometer
1
are available to fit the Gilford 2000 to your application.
gilford
(IS Mono
