The A260/A280 ratio method estimates protein by measuring the absorbance maximum at 280nm caused by the amino acids, , and . Since also absorbs in the UV range, we can correct for this contaminate by measuring the absorbance maximum at and using the following equation: When extrapolated from a standard curve, the Bradford data indicates the amount (in ) of protein found in a sample. If you know the volume of sample that was added to the assay then you can calculate the protein of the sample. The coomassie blue dye in the Bradford assay specifically binds primary ¬¬ and groups of the amino acid side groups of the proteins. The more the dye binds to the sample, the the blue color will be, and the absorbance at 595¬nm will be. A sample with an unusually number of [give a specific example] amino acids will underestimate the total amount of protein present in the sample.

By way of introduction, A260/A280 ratio is use to measure Protein Contamination. This procedure was first described to measure protein purity in the presence of nucleic acids. However it is now commonly used to assess protein contamination of DNA. The method to determine the concentration of protein contamination by using A260/280 ratio method is well explained below by filling in the missing words.

Explanation:

The A260/A280 ratio method estimates protein __purity___ by measuring the absorbance maximum at 280nm caused by the amino acids__cytosine___, Adenine, and ___Guanine Since ___Spectrophotometer also absorbs in the UV range, we can correct for this contaminate by measuring the absorbance maximum at 260nm and using the following equation: Concentration (µg/ml) = (A260 reading – A320 reading) × dilution factor × 50µg/ml___ When extrapolated from a standard curve, the Bradford data indicates the amount (in _ug__ ) of __unknown ___ protein found in a sample. If you know the volume of sample that was added to the assay then you can calculate the protein concentration ___ of the sample. The coomassie blue dye in the Bradford assay specifically binds primary ¬¬___sulfonic___ and __positive amines__ groups of the amino acid side groups of the proteins. The more the dye binds to the sample, the _anionic_ the blue color will be, and the absorbance at 595¬nm will be_shifted Amax___. A sample with an unusually __protein___ number of ___280nm of Tyrosine __ [give a specific example] amino acids will underestimate the total amount of protein present in the sample.

c

explanation:

well, i believe that the answer is 2. : 3