LDH A
LDH B
LDH
LDH C D
LDH/ Ι /LDH Ε/
Γ- / F
The chart above demonstrates the kinetic spectrophotomefric assay of lactic dehydrogenase (LDH). The activity of this.enzyme is frequently measured in serum of patients suspected of having had a heart attack. The decreasing absorbance " A " at 340 ηψ is recorded against time as LDH catalyzes the reaction. _|_ |_p|^ pyruvate + DPKH
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ΟΡΗ + H+ + lactate
The rate of this reaction (slope of d A / d t during the initial " O " order portion) is a measure of the enzyme's activity. Extreme slopes and/or deviation from linearity are indicative of an LDH abnormality. 30 production runs in ό groups are recorded on one chart, at 3 minutes/ group-
NEW AUTOMATIC TECHNIQUE REDUCES ENZYME ANALYSIS COSTS You can d o all of your reaction kinetics experiments on this o n e instrument, a n d still have a double-beam, scanning UVVisible S p e c t r o p h o t o m e t e r f o r b i l i r u b i n , barbiturate and salicylate analyses. The Automatic Multiple Sampling System using Perkin-Elmer's M o d e l 202 Spectro p h o t o m e t e r , saves y o u vital l a b o r a t o r y
a n a l y s i s time in c l i n i c a l serum studies. Kinetic reactions may be studied spectrophotometrically, o n a production scale of hundreds of analyses per day, at a mini mum cost per analysis. The analysis proceeds at a fixed w a v e length of light. The wavelength you select is held constant while the decrease in ab sorbance of one of the reactants is re c o r d e d as a function of time. Perkin-Elmer's Automatic Multiple Sampling System features... • A double beam, direct absorbance re cording spectrophotometer with analytical accuracy of ± .01 absorbance units; • A unique d o t readout system that pro
vides, on one chart, a complete continuous record of absorbance as a function of time for a batch of 5 samples plus a separate reference blank; • A t h e r m o s t a t e d sample c o m p a r t m e n t , with temperature control within ± 0.5 C from 2 0 ° to 5 0 ° C plus automatic sample positioning,· • A n a d j u s t a b l e time interval b e t w e e n sample readings of 3 to 120 seconds. For more information about this new en zyme analysis technique plus details on the Perkin-Elmer M o d e l 202 S p e c t r o photometer write t o : Instrument Division, P e r k i n - E l m e r C o r p o r a t i o n , 705 M a i n Avenue, N o r w a l k , Connecticut.
PERKIN-ELMER
