> I would like to estimate alpha amylase in phosphate buffer
> quantitatively. please give me the correct procedure. the problem is I
> didn,t get any colour during the lowry's procedure. i did with many
A simple check is the absorbance at 280 nm, which is caused by aromatic
amino acids in the protein. The Bradford dye binding assay is also quite
Have you done a positive control for your Lowry assay (BSA or
immunoglobulin solutions of known concentrations)? Not only to make a
standard curve, but also to know that you didn't mess up the assay.