Hello,
We bought pNPP tablets and 5X buffer ( diethanolamine) from Pierce in our laboratory. I have to make 300mM stock solution, (as i can't go to lower concentration for making stock) and it is not dissolving after vortexing it more than 1 hour. Does anybody have any idea to resolve this problem?
Thanks
Vinita
Hello
Dear Vinita
kindly check your solution pH. It should be basic. you can use two buffer for the solubility of pNPP tab.
pNPP substrate solubility buffer:
1. Diethanolamine Buffer (1 M diethanolamine buffer, pH 9.8, with 0.5 mM MgCl2) Add 97 ml of diethanolamine and 100 mg of MgCl2 to 800 ml of water, adjust pH to 9.8 with 10 M HCl and bring the volume to 1 L with water.
Glycine Buffer (0.1 M glycine buffer, pH 10.4, with 1 mM MgCl2 and 1mM ZnCl2) Add 7.51 g of glycine , 203 mg of MgCl2, and 136 mg of ZnCl2 to ∼980 ml of water and mix. Adjust pH to 10.4 with 19 M NaOH and bring the volume to 1 L with water.
I hope this can solve your problem.
Dr. SSY
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