Fig 3.

The immunodominant membrane-associated antigen is found only in B. microti-infected red blood cells. Triton X-114-extracted proteins (3.5 μg/lane) from uninfected (U) and B. microti-infected (I) red blood cell membranes were resolved on an 8 to 16% polyacrylamide gel and transferred to PVDF. PVDF sections were incubated with either serum from a confirmed-babesiosis patient (Human Serum) or a mouse monoclonal antibody raised against rBmSA1 protein (mAb 3A6D). Bound IgG antibodies were visualized as described for Fig. 1. The positions of molecular mass markers (in thousands) are indicated on the left. Monoclonal antibody reactivity confirmed the identity of the immunodominant protein band in the parasitized red blood cell detergent extract as BMN1-9/BmSA1 (indicated by the arrow).