Table 3.

Reciprocal titers of neutralizing activity in individual plasma samples against individual isolates from HIV-1 and HIV-2 panels^a

^aThe given reciprocal titers correspond to 1/dilution of plasma giving the 30% inhibitory concentration (IC₃₀) in the plaque reduction neutralization assay applied, and boxes are color coded as follows: white, <40 to 160; yellow, 320 to 1,280; orange, 2,560 to 81,920; red, 163,840 to 2,621,440. Magnitude of neutralization was then calculated according to the formula [log 3(highest dilution giving neutralization/100) + 1] and corresponds to titers as follows: <40 = 0; 40 = 0.166; 80 = 0.797; 160 = 1.428; 320 = 2.059; 640 = 2.69; 1,280 = 3.321; 2,560 = 3.952; 5,120 = 4.582; 10,240 = 5.213; 20,480 = 5.844; 40,960 = 6.475; 81,920 = 7.106; 163,840 = 7.737; 327,680 = 8.368; 655,360 = 8.999; 2,621,440 = 10.261.