TABLE 1.

Percentages of HIV-1-infected cells staining above background by flow cytometry analysis following incubation with ant-Env Abs and MAbs under different conditions^a

Conditions of incubation (°C/min)	Ab or MAb used	% SF-2-infected cells staining, gate 2	% RF-infected cells staining, gate 2
4/30	None	1	<1
	Seropositive sera	100	100
	4117C	96	96
	41148D	80	98
37/30	None	<1	<1
	Seropositive sera	100	100
	4117C	93	92
	41148D	67	86
4/30, then 37/30	None	<1	<1
	Seropositive sera	100	100
	4117C	97	97
	41148D	71	96
4/30, then 37/60	None	<1	<1
	Seropositive sera	100	100
	4117C	96	92
	41148D	72	85
4/30, then 37/240	None	<1	<1
	Seropositive sera	100	100
	4117C	97	93
	41148D	74	88

^aAll incubations were done under the conditions given in the table using either no Ab or MAb, pooled seropositive sera at 10⁻³ dilution, or 4117C or 41148D at 20 μg/ml in a buffer containing 10 mM NaN₃ as described previously (1). An aliquot of washed cells from each of these incubations was then counted for viability, while the remainder were reacted with fluorescein isothiocyanate-conjugated goat anti-human IgG at 4°C prior to measurement of fluorescence intensity by flow cytometry as described previously (1). Cell viability after the 4-h incubation at 37°C (final rows of table) was ≥75%, while for all other conditions, it was ≥95%.