FIG. 4.

Analysis of indeterminate sera with widely ranging r-DME-M reactivities. The scatter diagram displays the reactivities (absorbance at 450 nm) of sera manifesting weak and strong reactivities towards the r-DME-M protein used as the capture antigen in the in-house IgM ELISA. The IgM status of the sera determined by the PanBio strip test (PanBio) or the in-house IgM ELISA (r-DME-M) is shown in the inset; the subgroup, with reference to Table 2, to which the serum belongs is shown in parentheses. The dotted line indicates the cutoff absorbance (0.25 at 450 nm) used to designate samples as either positive or negative.