Final answer:
The technique known as Polyacrylamide Gel Electrophoresis (PAGE), often combined with SDS, is used to separate cellular proteins by net charge or size, and then visualized with special stains.
Step-by-step explanation:
The technique used to separate cellular proteins for analysis is called Polyacrylamide Gel Electrophoresis (PAGE). This method involves the use of a gel matrix composed of polyacrylamide and can separate proteins based on their net charges or size when combined with sodium dodecyl sulfate (SDS).
For a more detailed analysis, a two-dimensional approach can be applied, which separates proteins based on both their isoelectric points and size through Isoelectric Focusing (IEF) followed by PAGE. The separated proteins are then visualized using stains like Coomassie blue or silver stain.