protein suspended in diff buffer changes mobility - Will differnt salt concentration in buffer interfe (Jun/10/2005 )
Does anyone know if a high salt concentration in the buffer dissolving the protein change the mobility ? recently, i run a SDS-PAGE . my target protein was either dissolved in buffer A or buffer B (higher salt concentration). it seems the protein dissolved in buffer B migrating faster than that in buffer A.
recently we bought a protein marker, and as reported in the manual, different running buffers changes the apparent molacular weight of their peptides. Hence i assume different salts concentrations modifiy the mobility of protein. Seems SDS may be more recruitede by the proteins and it's salt environment...
Different concentrations of salts can not olny change the mobility, but distort the migration pattern as well.
We encountered this problem when we eluted protein from beads with solutions of different salt concentrations.
To avoid this, we used dialysis, removing excess salts. For the methods, refer to lab manuals such as Protein Purification by Robert K. Scopes.
Running gels at very low voltage can also help salts dissipate during electrophoresis.
Hope this helps.