TABLE 2.

Avidity measurements for a panel of 16 sera after elution with increasing concentrationsa of NaSCN

SerumbWAcAIdSerum dilution factor% Reduction in OD450e
10.3587.525040.1
20.4110025032.8
30.1515.410067.7
40.2537.515047.1
50.4120.55063.1
60.67100.515075.8
70.213015058.6
80.129608,00078.2
90.251,0004,00053.6
100.377420037.7
110.285820041.3
120.304515044.2
130.1742.525062.8
140.132620081.7
150.44225039.1
160.5410620020.6
PSAB-900.32128.8400NA
  • a Concentrations were 0 to 4 M.

  • b Sera 1 to 7 were prevaccination and sera 9 to 16 were postvaccination sera. PSAB-90 results represent the means of four independent assays.

  • c Determined as given under “Data analysis” in Materials and Methods.

  • d Calculated by multiplying the WA by the dilution factor.

  • e Since this avidity assay does not include a standard in the assay plate, we could not determine the percent reduction in concentration, but rather determined the percent reduction in OD450. NA, not applicable.