Neutralizing activities of combinations caprine E2 antibodies as measured by RT-PCR and real time PCR. Figure 10a Agarose gel electrophoresis of nested RT-PCR products of HCV 4a infected Huh7.5 cells to assess the optimum combinations of caprine E2 antibodies that block the viral infection into cells. Huh7.5 cells were infected Invitro using (virus + Ab) mixes each was made up of a pool of 10 HCV 4a positive sera (1.5 × 106-3 × 106 copies/ml) mixed with different combinations of caprine anti p430, anti p517 and anti p412Abs. Cells were preincubated with virus/Ab mixes overnight at 4°C. Cells incubated with HCV pool serve as positive control; lane 1. Mixes containing anti p430 showed partial inhibition of intracellular viral replication (lanes 2 and 3). Total blockage of HCV RNA replication inside Huh7.5 cells was achieved by a combination of caprine anti p517 and anti 412 Abs (lane 4). Products of non-infected Huh7.5 cells as negative control were presented in lane 5). M is a molecular weight standard DNA marker (100 basepair; JenaBioscience, Germany). Figure 10b Qualitative evaluation of combined effect of goat E2 antibodies that block HCV infection invitro. The results obtained revealed that although the mix of goat anti peptides 430 & 517 and the mix of anti p430 & anti p412 didn't block the viral replication but yet it was delayed such that the amplification started at cycle 32 and cycle 33, respectively, instead of cycle 16 as it was shown for the infected Huh7.5 cells (positive control). On the other hand the mix of the goat anti p412 & anti p517 showed, similar results as in negative control uninfected Huh7.5 cells, without any significant amplification (below the cutoff line), indicating complete viral inhibition.