Samples may be taken from whole tissue or from cell culture.
In most cases, solid tissues are first broken down mechanically using a
blender.
It should be noted that bacteria, virus or environmental samples can be the
source of protein and thus Western blotting is not restricted to cellular studies
only.
Assorted detergents, Salts, and buffers may be employed to encourage lysis of
cells and to solubilize proteins.
Tissue preparation is often done at cold temperature to avoid protein
denaturing.