The molecular weight of my protein sequence is 41 kDa. The SDS-PAGE result demonstrated its size 36 kDa. What are the reasons behind that?
it depends on what percentage of gel you have used- 36 and 41 seems close to me.
Determine the size with gel filtration chromatography or more easily accurately with MALDI TOF
Hi !
SDS-PAGE is just only for estimation of molecular weight of proteins and not the exact value.It gives you a range at which your protein belong. You can use 12%SDS-PAGE to estimate your MW of protein.
All the best.
Hi, Rashid,
It's one of the draw backs of SDS PAGE.!
I would like to give one example; actual molecular wait of p53 (tumour suppressor) is 43.7kd but the band appears on the membrane corresponding to 53kd and the resaon behind that is, p53 is proline rich and hence migration in the gel is altered.
So donnot stop your experiment at SDS PAGE. Proceed with WB, use suitable primary and secondary antibody to validate your results.
Hope this would help you.
Best regards.
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