General cell lysis question - whole cell lysates need to be centrifuged? (Jul/14/2009 )

I am confused by something....

If a cell lysis buffer is supposed to give you whole cell lysate (membrane and cytosolic proteins) why is there cell debris? What is it?

bits that resisted going into solution, especially insoluble proteins and bits bound up in DNA.

the cell debris is the parts of the cell that are not soluble in the detergent. A lot of the cytoskeletal components and membrane components will not solubilize in the detergent solution and thus are pelleted out.