Some Minor Questions Re SDS PAGE :

[Mehdi Alimadadi]

Dear Scientists,

I need answers to the following questions:

1.  Should the protein standards be diluted with loading buffer before
loading or
     it is not needed?

2.  Do the protein standards also need to be boiled before loading?

3.  Once boiled for 5 min with loading buffer, the protein stock samples
could be
     stored in -20 but do they need to be boiled again each time before
loading?

4.  When I have far different concentrations of proteins, do I need to
precipitate and dilute again in order to have approximately similar
concentrations within equal total volume, in order to have a perfect run?

Thanks, in advance