PAGE beginner

[waffaa_qm]

Iam beginner in learning SDS PAGE
Iam in master degree
my problem is when I work with gel 12% get good bands but if I work with gel 6% the bands is very light even I put the same concentration of sample in wells in the two gel
so what is the problem
And how can I analyze the bands by computer
please anyone help me
Thanks

[mara1412]

Hi,
what is the molecular weight of your protein of interest? You've got to choose the right acrylamide concentration for your protein. If you want to see good bands for heavy proteins (> 75kda) you should use 6-8% acrilamyde gel, while if your protein of interest is not so big(< 75kda) the right concentration should be between 9-12 %.
Mara

[waffaa_qm]

hi mara Thank you very much for your replying
and I didnot search for certain protein . my research is identifying the meat according to species by electrophoresis
so do you have any recommindation and how can I analyze the photo of the gel
please reply soon
thanks