Polyvinylidene fluoride (PVDF) film, which is commonly used as a kind of solid phase support, is commonly used in Western blotting. The PVDF membrane is hydrophobic, and the pore size of the membrane is large and small. With the decrease of the pore size of the membrane, the membrane is bound to the binding of low molecular weight protein. More than 20000 of the protein using 0.45um membrane, less than 20000 of the protein using 0.2um membrane. PVDF membrane pretreatment when using methanol, the purpose of treatment is positive group activation on the membrane, making it easier to combine with negatively charged protein. PVDF film has high mechanical strength, and it is an ideal solid phase support material in imprinting method.