Electrophoretic profile of fibrin clots. SDS-PAGE showing fibrin chain profiles of clots generated in the absence (odd-numbered lanes) and presence (even-numbered lanes) of Ca²⁺ from the citrated plasma of II.1, II.2, their mother (I.2), brother (II.3), and his children (III.1, III.2). II.1 and II.2 lack normal α chain, and a much shorter constituent chain (α^Keokuk) that cannot produce cross-linked α_n polymers is seen in II.1, II.2, II.3, and III.1 samples.