Dear Isarin Thanaboonyawat,

First of all you should collect your cells in a 10 ml PBS after trypsinization or scrapping and then centrifuge to pellet down the cells. Before centrifugation mix cells well and count the cells using hemocytometer. Now carefully remove PBS without disturbing cells. Now you can lyse your cells by adding 0.2 or 0.3 ml pure water (may contain 0.1% triton 100X)  and again centrifuge at 10000 rpm and use supernatant for assaying SOD or catalase or protein estimation. 

Live cell count should be done by using hemocytometer (using coomassie brilliant blue) and cell can be lyse using lysis buffer (commercially available or can be prepared). 

Dear Isarin Thanaboonyawat,

First of all you should collect your cells in a 10 ml PBS after trypsinization or scrapping and then centrifuge to pellet down the cells. Before centrifugation mix cells well and count the cells using hemocytometer. Now carefully remove PBS without disturbing cells. Now you can lyse your cells by adding 0.2 or 0.3 ml pure water (may contain 0.1% triton 100X)  and again centrifuge at 10000 rpm and use supernatant for assaying SOD or catalase or protein estimation.