Giraldo Giraldo, John JairoGómez Oquendo, JorgeVásquez Araque, Neil2013-04-162013-04-1620121794-4449http://hdl.handle.net/10567/895Introduction. Great efforts have been made in order to improve the cryopreservation of embryos. Nevertheless, one of the main problems is the sensible they are to cryopreservation, due to the bad effects of low temperatures and the concentration of cryoprotectors. Given this, the use of combinations of cryoprotectors has been proposed in order to reduce the harm produced by cryopreservation. Objective. To evaluate the effect of dymethylformamide (DMF) on the post-vitrification feasibility of in vitro bovine embryos. Materials and methods. 123 in vitro produced and vitrified in open pulled straws (OPS) embryos were randomly distributed according to the study groups (T1: DMSO + DMF 15%, T2: DMSO + DMF 20% and control: EG + DMSO 20%). After the de-vitrification, the embryos were cultivated and the re-expansion percentage was determined at 6 hours and its maintenance, at 18 hours of cultivation as a parameter of embryonic feasibility. Results. When the re-expansion of vitrified embryos in the T1, T2 and control were determined at 6 hours (61,9%, 91,6% and 63,8%) and at 18 hours (83,3%, 91,6% and 63,8%), the highest re-expansion percentages were found in the combinations with DMF. Conclusion. The combination of the 20% DMSO cryoprotectors +20% DMF during the vitrification of in vitro produced bovine embryos + 20% DMF during the vitrification of the bovine embryos produced, keeps the morphology and the capacity to re-expand or recover the blastocoel, after the thawing.esCorporación Universitaria LasallistaIn vitroDimetilformamidaGanado - ReproducciónCriopreservaciónEmbriones bovinosVitrificaciónArticle