lowry assay - purposes of lowry aaay (Aug/16/2010 )

hi...
what purposes of lowry assay??
it is neccesary if i want to do protein profiling???
protocol to do lowry assay???
TQ

lowry assay is for quantitate your total protein amount.

protein profiling? You should be running 2D-PAGE gel, right? In order to profile your protein shouldn't you standardize your protein loaded into your gel?

I think most people don't use the Lowry assay any more. There are other assays that are more accurate for determining protein concentration, if that's what you want to do.

in ur opinion between lowry, bradford and bieuret assay which one is the best and accurate??

Probably Bradford is best.

Depends on your buffer etc... I would say BCA more stable, but Bradford is the most convenient.

bradford is very sensitive but may be the least accurate of your choices (it depends on using a proper standard, bsa is probably the least appropriate standard for most proteins) and is not truly linear in response (you can find a range that approximates linearity).

lowry and its offshoot bca are both sensitive and accurate but not as fast as bradford.

biuret is accurate but not as sensitive as lowry or bradford. it should be used for high concentration samples (>1 mg/ml).

for any of these methods you need to use proper blanks and standards to ensure accuracy.