Effects of polyclonal antibodies against rEF1a on erythrophagocytosis by E. histolytica. Percentage of amoebae with erythrocytes based on examine of 300 amoebae (mean ± SD): group Blank, treated only with incomplete medium (69.69 ± 3.60); group treated with rEF1a-immune mouse serum (polyclonal antibodies), 1:100 (55.50 ± 2.20 **); group treated with rEF1a-immune mouse serum (polyclonal antibodies), 1:200 (59.43 ± 0.82 **); group treated with PBS-immune mouse serum, 1:100 (72.51 ± 3.44); group treated with PBS-immune mouse serum, 1:200 (72.87 ± 6.15). ** As compared with control (group treated with PBS-immune mouse serum 1:100). p < 0.01 (Student’s t-test). Data are from three independent trials.