This compound can be used as a substrate in the assay of the
activities of glucose-6-phosphate dehydrogenase and glucose-6-
phosphatase. It can also be used for the preparation of other
The assay is based on the following reaction (Methods of Enzymatic Analysis, Bergmeyer, H.U. ed; Vol 3, 1238, 1974, Academic Press, New York).
0.055 M Tris-HCl, containing 0.0033 M magnesium chloride, pH 7.8.
Assay Mixture. Dissolve 50.3 mg NADP+ in 30 ml Tris buffer, pH 7.8. Adjust the pH to 7.8 with 1 M NaOH, then add 150 units of Glucose-6-P-Dehydrogenase (G6-P-DH, EC 18.104.22.168) and dissolve. This assay mixture is sufficient for ten assays. Prepare fresh prior to assay.
0.012 M Glucose-6-Phosphate. Dissolve 35 mg G-6-P in 10 ml distilled water. Prepare fresh.
Set spectrophotometer (equipped with strip chart recorder and temperature control) at 340 nm and 37°C.
Into a cuvette, pipette 3 ml assay mixture and incubate in spectrophotometer at 37°C for 3 minutes.
Record the initial absorbance at 340 nm (Ai).
Add 10 µl Glucose-6-P (substrate) to the cuvette.
Follow the reaction for 10 minutes at 37°C.
Record final absorbance at 340 nm (Af).
A = Af - Ai Total Vol. = 3.01 ml 282 =
MW of Glucose-6-P-monosodium salt (anhydrous) Sample Vol. = 0.01 ml