Table 2. Stability of the alphoid^tetO-HAC/tTA^VP64 in dox⁺ and dox⁻ medium in hamster CHO and human HeLa cells.

Hamster ovary CHO cells
# clonea	Medium	3 days	14 days
1	dox+	99%	77%
	dox−	99%	4%
2	dox+	99%	85%
	dox−	99%	5%
Human epithelium HeLa cells
1	dox+	99%	93%
	dox−	99%	2%
2	dox+	99%	92%
	dox−	99%	3%

^aFor each HAC-containing clone at least 130–140 metaphases were examined.