A general and mild procedure for the purification of rabbit Fab' antibodies

A mild procedure for the purification of rabbit Fab' antibodies is described. A small column of normal goat IgG-Sepharose 4B (3 cm x 5mm) was saturated with F(ab')2 prepared from rabbit anti-goat IgG, and anti-goat IgG Fab was eluted from the column by splitting the disulfide bond in the hinge of the F(ab')2 molecule using 10 or 12 mM 2-mercaptoethylamine at pH 7. The recovery of anti-goat IgG Fab' in the eluate was about 35% of anti-goat IgG F(ab')2 bound to the column, and the purity of anti-goat IgG Fab' eluted was more than 90%. This procedure may be applicable to most kinds of rabbit IgG antibodies and useful for various immunoassays.