Enzyme Activity Assays

Can I use cell culture samples in the COX Activity assay?
Cell culture samples are compatible with this kit. Since this is an activity assay rather than a quantitative immunoassay, there…
Tue, Jul 18, 2023

Can I use the COX activity kit to distinguish between COX-1 and -2?
The COX Activity kits measure activity alone, distinguishing between COX-1 or -2. In order to differentiate between the two enzymes,…
Tue, Jul 18, 2023

Can whole blood samples be used?
High background may result from the presence of hemoglobin in your sample. Hemoglobin (Hb) has a significant absorption at 340…
Tue, Jul 18, 2023

My first assay for total glutathione worked well, but when I repeated the assay to test the oxidized samples, the curve was essentially flat-to-negative.
Oxidized glutathione is very difficult to detect because it is rapidly turned over and converted, so there is only a…
Tue, Jul 18, 2023

Why and how should I treat my samples and the standard with 4-Vinylpyridine (4-VP)?
In order to measure oxidized glutathione (GSSG), you must eliminate GSH in the cell extract by treating with 4-VP, a…
Tue, Jul 18, 2023

What is the purpose of treating samples with 5% metaphosphoric acid (MPA)?
MPA should be added to fresh samples prior to sample handling or sample storage. That is required to deproteinize samples…
Tue, Jul 18, 2023

What is the principle of the Glutathione (GSSG/GSH) assay?
The Glutathione (total), detection kit is a complete kit that allows the determination of total, reduced, and oxidized glutathione concentrations…
Tue, Jul 18, 2023

What can interfere with the assay?
Reducing agents (such as ascorbic acid, beta-mercaptoethanol, dithiothreitol, and cysteine) and thiol reactive compounds (such as maleimides) are known to…
Tue, Jul 18, 2023

Values for this assay are reported as pmol/well. How can I convert the values obtained by this kit into a value that is more commonly reported in the literature, such as pmol/L (pM)?
Since the volume of sample added to each well is 50µL, results can be converted to molarity by multiplying by…
Tue, Jul 18, 2023

After having measured the total glutathione content, is it possible to use the same samples on the plate so as to continue the procedure and measure the oxidized form of glutathione?
The measurements of total and oxidized glutathione are two completely different events; it is therefore not possible to use the…
Tue, Jul 18, 2023