. Author manuscript; available in PMC: 2010 Aug 1.

Published in final edited form as: Gene Ther. 2009 Oct 15;17(2):238–249. doi: 10.1038/gt.2009.131

Table 1.

MTXr-Tyr22DHFR Enzyme Activity in DHFR-GFP hESC Extracts

	−MTX U/mg^a	−MTX p value^b	+MTX U/mg^a	+MTX p value^b
EFDIG-H9	15 ± 3	0.151	15 ±4	0.001
DL2G-H9	12 ± 8	0.988	13 ±7	0.007
CSIIEG-H9	12 ± 2		0

Cell lysates from transduced or untransduced H9 cells were assayed for DHFR activity in the presence and absence of 0.25 µM MTX. One unit of enzyme activity is defined as 1 nmol/min. Results shown are the mean of three assays ±S.D.

Enzyme activity in extracts from EFDIG-H9 cells and DL2G-H9 cells were compared to CSIIEG-H9 cells using an unpaired, two-tailed student’s t-test.