In order to prepare the bovine serum albumin (BSA) standard for this assay, it w
ID: 1066365 • Letter: I
Question
In order to prepare the bovine serum albumin (BSA) standard for this assay, it would be necessary to dissolve a sample of BSA in water or in a buffer, and allow the protein time to dissolve, (liter or centrifuge the solution (to remove any un-dissolved materials), and finally determine the exact concentration of the protein. UV absorption is a good way to determine the exact concentration. The published extinction coefficient for bovine serum albumin is E280^1% = 6.6. The concentration unit % solution) here are a little odd, and dates to the day before the .structure and molecular weight of the protein were known. A 1% solution is: 1% = 10 mg protein/1000 mg water Times 100% = 10 mg/m L Or put another way a 10 mg/mL solution will have an A_28O = 6.6.Let's say that 5 mL of a BSA solution is prepared, it's A_280 is read and A_280 = 0.82 2 What is tie concentration of the solution in mg/mL?Explanation / Answer
Concentration of BSA can be calculated using Beer-Lamber’s law as shown below:
A = bc
Where, A = absorption
= Extinction coefficient in (mg/mL)-1.cm-1
b = path length in cm.
c = concentration in mg/mL
Given value of extinction coefficient is for 10mg/mL. It can be converted into mg/mL as follows:
= 6.6 / 10 (mg/mL)-1.cm-1
= 0.66 (mg/mL)-1.cm-1
Thus, concentration of given BSA standard (A = 0.82)can be calculated using Beer Lambert’s equation as follows:
A = bc
c = A / b
c = (0.82) / (0.66 x 1)
c = 1.24 mg/mL
Thus, concentration of 5mL BSA solution is 1.24 mg/mL