In Bradford assay, what factors affect the measurement of enzyme (BSA) specific - (Dec/03/2006 )

That is, bovine serum albumin

The Bradford assay is a dye binding, direct, non-enzymatic spectroscopic method. The actual dye binding takes place via basic amino acids so the more of these in your protein, the greater the binding. pH may affect binding. As far as standards go, BSA is often used but you really ought to choose a standard that is similar to your own protein (pKa, size, hydrophobicity etc). i think there are sometimes problems about linearity in the standard curves.

Other factors that affect spectrophotometric measurement of any protein include stray light interference, bandwidth & chemical interference: this method is for total protein and isn't specific for BSA (the bromcresol green method would be better for that).

All that said, it's a robust and sensitive technique.

high or low pH will alter protein conformation , in other words improper pH can denature proteins including their binding site

As Strawberry says, conformational changes occur. Also, de-protonation of amino groups on the side chains occurs. These are the amino acids involved in binding the dye so even if these side chains still protrude out of the protein they can't actually bind since their leaving group has already left.

Several detergents interfer the assay. You should always run one tube with the same buffer composition as your sample as a blank.