Summary of the primary expression screening
. | No. tested . | No. β-gal positive (%) . |
|---|---|---|
| ES cells on gelatin | 846 | 192 (22.7) |
| Differentiated ES cells on OP9 | 833 | 119 (14.3) |
. | No. tested . | No. β-gal positive (%) . |
|---|---|---|
| ES cells on gelatin | 846 | 192 (22.7) |
| Differentiated ES cells on OP9 | 833 | 119 (14.3) |
R1 ES cells were electroporated with IRESβgalNeo(-pA) gene-trap vector and cultured with G418. A total of 864 G418-resistant ES clones were cultured on gelatin in ES cell medium for 2 days or on OP9 feeder cells in ES differentiation medium for 5 days, followed by X-gal staining. Some ES clones did not grow at all. The OP9 feeder cell layer with ES cells was sometimes peeled off during culture or X-gal staining.