Question

I am doing a bradford assy of fraction chart on LDH for biochemistry lab. What does it mean or how to you solve when it ask "uL needed for 20 ug." For example, for my crude extract I have 4.0 uL used, Abs595 was 0.7010, ug of protein was 8.122, and [protein] (ug/uL) was 2.03. Any helpful solvers?

Answer 1

Ans. Such statements may appear when you are provided a stock protein solution of known concentration and asked to take specific quantity of protein for preparing a standard aliquot or similar solutions.

The data provided in question do not seem to accurately correlate. It’s not wise to proceed without the linear regression of Bradford assay graph for considering the concentrations and absorbance.

However, we don’t need them to explain “uL needed for 20 ug”.

# Given,[Protein] = 2.03 ug/ uL , that is, 1 uL of solution contains 2.03 ug protein.

Note that ug is a unit of mass. 1 ug = 0.001 mg

                        uL is a unit of volume. 1 uL = 0.001 mL

Now,

How much volume (uL) of above protein solution do you need to take 20.0 ug protein?

Solution: Volume of solution required = Required mass of protein / given [Protein]

            Or, Volume of solution required = 20.0 ug / (2.03 ug/ uL)

                                                                        = 9.85 uL

So, if you take 9.85 uL of the above protein solution, you take 20.0 ug protein in it.

# Similarly, any required volume can be calculated.