Sephadex G-75 chromatographic profiles of 40, 80, and 160 mM NaCl-DEAE fractions from the buffalo placentas. The column (5 × 100 cm) was previously equilibrated with 5 mM ammonium bicarbonate buffer (pH 7.5). Elution of proteins (O.D. at 280 nm) is indicated by a black line while immunoreactivity RIA-708) is indicated by a grey line. Stippled areas indicate the most immunoreactive fractions.