Table 1.

The transformation efficiency of C-169 cultured in four different temperature regimes.

Field strength E = V/d	Number of colonies resistant to hygromycin B(*)
	4 °C	10 °C	20 °C	27 °C
9,5 kVcm−1	69 ± 22	13 ± 6	21 ± 7	58 ± 26
6,8 kVcm−1	49 ± 13	7 ± 4	14 ± 9	36 ± 11

Cells were electroporated, and then, they were grown initially in liquid medium supplemented with hygB (40 μg/ml) and then on agar plates with hygB, as described in the “Materials and methods” section. The colonies were scored after 6 weeks of growth on plates. Samples electroporated in the absence of pCAMBIA1391Z did not give any resistant colonies.

⁽*⁾ Mean ± SE (n = 3). Student's t-test revealed that differences were statistically significant.