i do it but i can't understand the mechanism and how we can estimation our protein using Bradford soln ?
How are you going to estimate the amount of your protein without having the standard curve in the first place? http://en.wikipedia.org/wiki/Bradford_protein_assay basic information as to how bradford test works.
That's not matter only of the Bradford solution and protein concentration estimation, but of any quantification. or any quantification you need to know the dependence of your signal (absorbance, peak area on chromatogram, any other signal you use) in dependence on quantity of your analyte.
People typically use a commercially available protein as the standard for the Bradford assay or one of the other colorimetric protein assays (BCA, Lowry), most often bovine serum albumin, but sometimes ovalbumin or immunoglobulin. This introduces the possibility of a systematic error in the estimation of the protein concentration of a sample because the relationship between the absorbance and the concentration differs between proteins because they have different amino acid compositions. Ideally, one would use a standard consisting of the same protein that is being quantified, but such a standard with known concentration is usually not available. So a compromise is to use a different protein that can be obtained or dissolved at a known concentration.
If a really accurate knowledge of the protein concentration is needed, and a fairly large amount of the protein is available, you can dialyze it extensively against water and lypohilize it, then weigh the dry protein. This material can also then be used subsequently as a standard for the Bradford assay.
Quantitative amino acid analysis is another option for obtaining a standard-independent measurement of the protein concentration of a sample. This can be done by a service company.
thanks for all
what do make me confuse is that we use different protein like BSA for quantification having different amino acid ?
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