将下列英文翻译。 A western blot (immunoblot) of antigens separated from a complex mixture by SDS-PAGE( or by isoelectric focusing) can be carried out. This employs transverse electrophoresis on yo polyvinylidene difluoride (PVDF) or nitrocellulose membranes, where the proteins bind nonspecifically and are subsequently identified by staining with appropriately labeled antibodies. Obviously, such a procedure will not work with antigens which are irreversibly denatured by this detergent, and it is best to use polyclonal antisera for blotting to increase the chance of including antibodies to whichever epitopes do survive the denaturation procedure; a surprising number do (figure 6.18). conversely, the spectrotype of an antiserum can be reveraled by isoelectric focusing, blotting and then staining with labeled antigen. Figure 6.18. Western blot analysis of human polymorph primary granules with sera from patients with systemic vasculitis. Human polymorph postnuclear supernatant was run on SDS-PAGE.(a) Gel stained for protein with Coomassie Blue. Number refer to molecular weight marker(kDa). (b) Blots from gel stained with serums from fiver patients and one control and visualized with alkaline phosphatase-conjugated goat-anti-human IgG. Three different patterns of autoantibody reaction are evident. The antibodies used for immunoblotting are usually labeled with enzymes or biotin followed by enzyme-labeled avidin.