Table 1.

Expression of β-gal gene

Gene transfer agent	Cell line	Expression, % of clones				No. of clones evaluated	MMR status
		With 80–100% blue cells	With 50–80% blue cells	With 20–50% blue cells	With <20% blue cells
Gal/Neo virus	HT29	93	4	1	2	190	Proficient
	SW480	91	7	0	2	122	Proficient
	SW837	95	2	0	3	500	Proficient
	Colo205	45	20	20	15	285	Proficient
	Caco2	60	19	5	16	74	Proficient
	HCT116	4	7	8	81	84	Deficient
	LoVo	2	2	6	90	214	Deficient
	SW48	10	6	12	72	405	Deficient
	RKO	10	8	12	70	318	Deficient
	DLD1	26	20	20	34	328	Deficient
Gal/Neo plasmid	HT29	12	7	8	73	464	Proficient
	HCT116	0	0	1	99	254	Deficient
Gal/Hyg virus	HT29	95	1	1	3	2602	Proficient
	HCT116	13	13	27	47	557	Deficient
	HCT116+ch3	11	11	20	58	670	Proficient

MMR-proficient and MMR-deficient cell lines were infected with the retrovirus Gal/Neo (lines 1–10) or were transfected with the plasmid used for Gal/Neo virus production (lines 11 and 12) and were selected with G418. Alternatively, cell lines were infected with the retrovirus Gal/Hyg (lines 13–15) and selected with hygromycin. Individual clones were stained with X-Gal to detect β-gal expression. For each clone the percentage of cells expressing β-gal (blue cells) was determined.