Mark your protein with an epitope such as 3X-FLAG or 6xHis-Tag, among others. Then you can purify your protein by affinity columns. Moreover, you can identify by WB.

Best regards.

Are you cloning a specific set of proteins or interested in full protein profile? Your method of choice will be highly dependent on your goal.

To collect extracelllar proteins, I would collect the medium and precipitate the proteins (by NHSO4), while sonication is my first method of choice to obtain cellular proteins.

Hi Subham,

Do you need to purify individual proteins from each fraction, or do you want to extract  all proteins from both intracellular and extracellular fractions? 

Hi Berardo, Irfan and Aydan,

Thank you for taking out time to respond to my question.. I actually need to isolate ALL proteins, both intracellular and membrane bound..I do not need to purify them individually, I just require all the proteins in en masse.. Hence, a suitable method for this objective would be helpful..

Subham

Collect the medium, concentrate by amicon or precipitate the proteins by ammonium sulfate, and then dialysis to change to suitable buffer.

Break the cells with your method of choice (sonication/french press etc), centrifuge at low speed to remove cell debris. You can remove membrane bound proteins by using high speed centrifugation (like 40K rpm for 1 hour), the supernatant will be cytoplasmic proteins.

It should be simple because you don't need to purify. This should be straightforward and simple. The best protocol is which you  make for yourself. Goodluck.