Table 4. Effect of 1.25 mM caffeine treatment delayed activation according to the time duration on preimplantation development of porcine SCNT embryos.

Caffeine treatment time (conc.)	No. of reconstructed oocytes	No. of embryos (%; mean ± SEM) developed to
		2-cell	4-cell	8-cell	Morula	Blastocyst
1 h (0 mM)	159	116 (72.9 ± 4.8)	105 (66.0 ± 5.2)	70 (44.1 ± 6.2)	36 (22.9 ± 2.6)	24 (15.2 ± 1.9)*
4 h (0 mM)	178	139 (78.0 ± 4.9)	125 (70.3 ± 4.4)	72 (40.6 ± 3.5)	45 (25.2 ± 2.7)	23 (12.9 ± 3.0)*
4 h (1.25 mM)	178	145 (81.2 ± 5.5)	128 (71.9 ± 6.2)	76 (42.8 ± 3.8)	51 (28.8 ± 1.7)	40 (22.5 ± 2.1)†

SCNT, somatic cell nuclear transfer; SEM, standard error of the mean; conc., concentration.

^*,†Values in the same column with different superscript letters are significantly different (p < 0.05).