## Homework Statement

Hi, I have one more question about the Bradford Assay. This one involves dilution.

Given 1ml of protein A, I am to determine its protein concentration (in mg/ml) using Bradford Assay (with known BSA protein standards).
Also, Under a 5 times dilution, the average absorbance is 0.497.

## Homework Equations

The standard curve I obtained is: ## The Attempt at a Solution

From the standard curve,
y = 66.717x
With absorbance = 0.497
0.497 = 66.717x
x = 0.00744 ug/ul
Since there is a dilution factor of 5
New x = 0.00744 * 5 = 0.0372 ug/ul = 0.0372 mg/ml ?? (is this correct?)

However, the correct answer is 0.372 mg/ml . What did I did wrongly??

Bystander
Homework Helper
Gold Member
x = 0.00744 ug/ul
Looks good.
New x = 0.00744 * 5 = 0.0372 ug/ul = 0.0372 mg/ml ??
Looks good.

Answer keys in textbooks are "edited/proofed" by "slave labor," aka grad students and post-docs. Often, "half" changes are made after proofing --- problem statements change, and answers don't.

Borek
Mentor
In your other question you clearly ignored part of the information given, hard to comment on this one not seeing the whole problem.

Bystander