Enzyme Activity Assays
Quantify enzyme activity in cells, tissue and biological fluids. Kits cover dehydrogenases, phosphatases, transaminases, oxidases, proteases and antioxidant enzymes.
LDH, G6PD, glutamate dehydrogenase, pyruvate kinase, aldehyde and alcohol dehydrogenase and TCA cycle enzymes.
ALT, AST, ALP, acid phosphatase, gamma-GT, amylase, lipase, creatine kinase and cholinesterase.
SOD, catalase, glutathione peroxidase, MPO, xanthine oxidase, ACE, DPP4, trypsin and pepsin.
Enzyme activity assays report how much functional enzyme is present, not just how much protein. A substrate is converted to a coloured or fluorescent product, and the rate of signal change is proportional to activity in the sample.
Activity is sensitive to temperature, pH and sample handling, so keep samples cold, avoid repeated freeze-thaw cycles and run the standards and controls supplied with each kit.
Concentration, measured for example by ELISA, tells you how much enzyme protein is present. Activity tells you how much of it is catalytically functional.
Colorimetric kits need only an absorbance reader. Fluorometric kits offer higher sensitivity for low-activity samples.
Many activity kits can be adapted for inhibitor testing, and dedicated inhibitor screening kits are also available.