PURPOSE

To gain knowledge about the methods for protein determination and determination of protein content of a solution by using Biuret method.

PROCEDURE

A series solution of Bovine Serum Albumin (BSA) was prepared with different concentrations from 0 to 10 mg/ml. These concentrations were prepared by using stock solution of 10 mg/ml BSA and distilled water. Firstly a blank solution was prepared by using 0 ml BSA and 1 ml distilled water to be used for calibration of spectrophotometer. Then 0,8 ml distilled water was added to 0,2 ml BSA and 2 mg/ml solution was obtained. 0,7 ml distilled water was added to 0,3 ml BSA and 3 mg/ml solution was obtained. 0,5 ml distilled water was added to 0,5 ml BSA and 5 mg/ml solution was obtained. 0,2 ml distilled water was added to 0,8 ml BSA and 8 mg/ml solution was obtained. Finally no distilled water was added to 1,0 ml BSA and 10 mg/ml solution was obtained. After that 4 ml Biuret reagent was added to these test tubes. After waiting for 30 min. the absorbance of each tube was read at 540 nm and the results were recorded. By using these values a standard curve was plotted as concentration (mg/ml) vs absorbance (A540) and the concentration of our unknown protein solution was found.

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