An alternative isoelectric focusing method for the A subunit of coagul
ation factor XIII (FXIIIA) subtyping is described which employs three
different carrier ampholytes, pH 4-6.5, pH 5-6 and pH 5-8 (2:2:1), and
sample application at the anode. With this technique ten common subty
pes, including a variant, were clearly and reliably identified in Japa
nese and Chinese population samples.