Question

Which method would you prefer to use when you have to separate different isoforms of a protein? sds-page 2-de 1-de bn-page?

Answer 1

 by performing 2D- gel electrophoresis: this step separates isoforms of proteins based on their molecular weight and isoelectric point (PI).

The PI is the ph at which a protein is neutral or has no net charge. So you can separate protein isoforms based on the differences on the net charge of each protein isoform.