Summary
A technique for the detection of von Willebrand factor multimers separated by discontinuous
SDS agarose electrophoresis has been developed using non-radioactive com-v pounds.
The multimeric patterns were visualized by monospecific anti-human vWF:Ag followed
by incubation with biotinylated antibody. After addition of avidin-biotin-peroxidase
complex, the peroxidase activitiy was detected by 4-chloro-l-naphthol, giving sharp
bands with a clear background.
By this method, the differences of vWF : Ag multimers could be easily observed between
normal plasma and the plasmas from variant type vWD (IIA, IIB, platelet-type). Large
and intermediate multimers were absent in the plasma with vWD type IIA, while only
large multimers were absent in the plasma with vWD IIB and platelet-type. The absence
of large multimers was also observed in two commercial F VIII preparations having
the ratio of vWF/vWF : Ag 0.18 and 0.63. The preparation with the ratio of 0.63 showed
the presence of larger intermediate multimers.
Electrophoresis in SDS 1.5% agarose gel revealed triplet structure of each small multimer,
and a relative increase of the smallest subband was observed in vWD IIA plasma, platelet-type
vWD plasma and commercial F VIII preparations.
The procedures described are easy and safe to perform and are useful for screening
or classifying cases with vWD in general laboratories.
Key words
SDS-agarose gel electrophoresis - von Willebrand factor multimers - Immunoenzymatic
stain - Avidin-biotin peroxidase complex - von Willebrand’s disease
