Figure 2.

Immunofluorescent staining of Cryptosporidium parvum oocysts with parasite-specific breast milk immunoglobulin A (IgA). Cryptosporidium oocysts treated without a primary antibody (A) or with breast milk (B) from mothers in the lower 50th percentile did not stain with CY3-conjugated goat antihuman serum IgA. C, Oocysts treated with high anti-Cryptosporidium IgA breast milk did stain with the CY3-conjugated secondary antibody, demonstrating the presence of IgA directed at Cryptosporidium oocyst within breast milk. Scale bar = 5 µm.