Figure 1: Comparison of three samples of IBs via hemagglutination. Lines A, B – negative control (no IBs); lines C, D – Sample 1; lines E, F – Sample 2; lines G, H – Sample 3 of IBs 2-fold diluted from column 1 to column 12 in 25 μl PBS and titrated with 50 μl washed human erythrocytes. Black frame –heamolysis; blue frame – prozone effect; red frame – positive hemagglutination; green frame – negative hemagglutination.