Hi there,

The easiest is to prepare both 0.1M solutions of KH2PO4(acidic form) and K2HPO4(basic form). Then add the latter to the former until the desired pH is reached. The pKa of the second acidic function of phosphoric acid being around 7, you may start directly by mixing equal volumes of both solutions (pH should be pKa). The main advantage of this approach is that the total concentration in phosphate remains constant at any stage of the preparation (ie. no need to adjust the volume at the end).

First, you must prepare phosphate buffer with below protocol. and than SOD, APX and CAT activities can be measured on the same extracts by grounding for exemple 0.5g of fresh material in 3 or 5 ml of phosphate buffer 0.1 M pH 7.5, containing 0.5 mM EDTA and 1 mM ascorbic acid. İf you want to measure POD,PPO enzyme activity, you can add to PVP (%1) inside of buffer mix. Good luck

ITS SO EASY READ PDF ATTACHMENT FILE

Okk thank you all ....

There are standard ready reckoner for preparing phosphate buffer. In case you don't find I am attaching the PDF file. The buffer is 0.1M now convert into the required concentration.