The broad-range Ampholine (LKB) 3.5–10 containing a mixture of materials with isoelectric points between pH 3.5 and 10 was found to correct the prolonged PTTK of factor VIII-deficient plasma, and this effect was investigated. Ampholines which are used as carrier ampholytes or pH gradient stabilizers in isoelectric focussing are condensation products of propionic acid and polyethylene polyamines.The most effective of the commercial Ampholine mixtures were found to be those with the most alkaline isoelectric points. Ampholine 9–11 at 0.2% concentration was found to have factor VIII and factor IX activity equal to that of normal plasma as well as somewhat less activity as factor XI. It had no significant correcting effect on plasmas deficient in factors V, VII, X, II or XII. In contrast to polyglutamic and polyaspartic acids which have also been reported to correct for factor VIII deficiency in the PTTK, Ampholine 9–11 was effective whether added before or after kaolin contact activation of the test plasma. However, Ampholine 9–11 inhibited contact activation of plasma in the absence of kaolin and showed less correcting activity in partial thromboplastin time tests utilizing activators other than kaolin.
Factor VIII-Like Activity of Basic Amphoteric Polyelectrolytes