I am studying the spectrophotometric assay of glutathione peroxidase. I want to know whether I can prepared the reduced glutathione previously and kept at 4oC for further use or not.
Dear Ankita,
I have not done systematic evaluation of its stability at this temperature, but cysteine oxidize at a rate of about 10-15% per day in the refrigerator (about 6oC). The best procedure is to freeze the samples in small amounts and used it after a maximal of two cycle of freezing and thawing. For GSH, we have not experienced any decrease in the thiol (reduced) content (by the Ellman's methods, i.e., using DTNB as color reagent) even after 4 cycles of freezing and thawing.
If you have any specific question, let me know.
Regards
Joao
Dear Ankita,
I have not done systematic evaluation of its stability at this temperature, but cysteine oxidize at a rate of about 10-15% per day in the refrigerator (about 6oC). The best procedure is to freeze the samples in small amounts and used it after a maximal of two cycle of freezing and thawing. For GSH, we have not experienced any decrease in the thiol (reduced) content (by the Ellman's methods, i.e., using DTNB as color reagent) even after 4 cycles of freezing and thawing.
If you have any specific question, let me know.
Regards
Joao
In addition to professor Rocha's answer, I do preserve my protein and enzyme sample in batches, the activity wasn't lost.
I believe it will work for gsh as well
Another point that you have to consider is the purity of the water. Small amounts (nmolar or even lower) of Cu+/2+ will facilitate a lot the oxidation of -SH groups from either cysteine or GSH.
GSH is better stored as powder at 4oC, but when dissolved it advisable to be stored as aliquots.
I totally agree with Prof Joao Batista Teixeira da Rocha and Dr Andrey Massarsky
regards
Hi
Normally, I prepare stock solution of GSH and I do not store it for more than 24h at 4 degrees.
- Badges
- Science topic
- Similar topics
- Microbiology
- Assays