Question

I've got to separate Escherichia coli proteins by SDS-PAGE electrophoresis.

Materials provided to me:
1X E.Coli cell pellet from 0.5 ml culture;
3ml of 0.6% SDS
2X Sample buffer [Composition: 20% glycerol, 100mM TrisCl pH 6.8, 4mM EDTA pH 8.0, 4% (w/v) SDS, 200 mM dithiothreitol, 0.001% (w/v) bromophenol blue]

I resuspended the E.Coli pellet in 0.5 ml of 0.6% SDS. This resuspension is called E.

Then I pipetted 20µl of E into a tube and added 20 µl of sample buffer. This is called G.

The question is: How much protein is present in 20 µl of sample G.?
And tell me what are the 3 major components of the sample buffer?

Answer 1

it's impossible to know how much protein there is in tube G without performing another experiment, e.g. uv-vis spectrophotometry (i.e. building a calibration curve).

Answer 2

If you mean to determine the absorbance of that protein, yes i performed it in the lab, got the value and estimated the concentration from the curve i did from a standard. That was another question in my practical. My question is the "How much" here literally means "concentration" of the protein in the sample? If yes, it means that two questions in my practical mean the same o.O? Does the question I asked here requires some calculation?

Answer 3

maybe he wants the number of proteins or moles

Answer 4

I got the solution today. thanks for your help though =)