Table 1.

Titers of pseudotyped vectors determined by X-Gal staining

env gene	Target cell	Titer, cfu/ml
Ampho MuLV	293	6  ×  105
	HeLa	5  ×  105
	HeL–CD4+	4  ×  105
	C8166	n.d.
HIV-1+	293	<1
	HeLa	<1
	HeLa–CD4+	<1
	C8166	n.d.
HIV-1 truncated‡	293*	<1
	HeLa	<1
	HeLa–CD4+	9  ×  104
	C8166*	3  ×  104
	BJAB	<1
	BJAB–CD4i	3  ×  103
	BJAB–CD4i	1.7  ×  104
	Jurkat	2  ×  104

 X-Gal, 5-bromo-4-chloro-3-indolyl β-d-galactosidase. n.d., not determined. 

^†Pool of hygromycin resistant colonies. 

‡ Infections carried out using supernatants from cell clone TELCeB6/pTr712-9. Cells marked with * were infected using supernatants from clone TELCeB6/pTr712-K14.