Vacuum-cooled liquid nitrogen increases the developmental ability of vitrified-warmed bovine oocytes

Abstract

The objective of this study was to determine the effects of vacuum-cooled liquid nitrogen on the development

Calves Born after Direct Transfer of Vitrified Bovine In Vitro‐produced Blastocysts Derived from Vitrified Immature Oocytes

“…Blastocyst rates similar to the one presented in this study (4–5%) have been demonstrated by others (3–8%) after minor modifications of the OPS vitrification technology (Le Gal and Massip 1998, 1999; Vieira et al. 2002; Santos et al. 2006).…”

“…Even though the permeability of oocytes is higher for DMSO than for EG (Agca et al 1997), in our study, oocytes were pre-equilibrated in a diluted (3%) EG solution, for a relatively large period for the achievement of an additional cell influx of this cryoprotectant (Papis et al 2000). Blastocyst rates similar to the one presented in this study (4-5%) have been demonstrated by others (3-8%) after minor modifications of the OPS vitrification technology (Le Massip 1998, 1999;Vieira et al 2002;Santos et al 2006). Such findings suggest that the cryoprotectant associations and exposure times are still the main limiting factors determining lower cleavage and blastocyst rates after vitrification.…”

“…Under this condition, the forced convection produces an unsaturated boiling state as LN 2 is super-cooled (£)200°C ¼ 'boiling off'), allowing a high heat conductance to increase dramatically the cooling rate. The super-rapid cooling into LN 2 at the 'boiling off' demonstrates the effectiveness of such approach for the vitrification of mature (Martino et al 1996;Arav and Zeron 1997;Arav et al 2000) and immature (Yavin and Arav 2001;Sanjay et al 2002;Santos et al 2006) oocytes. However, the limited available data supporting this notion still show low embryo yield after vitrification.…”

Genome Banking for Vertebrates Wildlife Conservation

“…Slush also significantly increases the cooling rate. Several studies have demonstrated the superiority of slush over liquid nitrogen (Arav & Zeron, 1997;Isachenko et al, 2001;Beebe et al, 2005;Santos et al, 2006;Lee et al, 2007;Criado et al, 2010) but some found little or no difference (Martino et al, 1996;Cuello et al, 2004;Cai et al, 2005) (Table 2). When cooled at such high cooling rates, oocytes spend very short interval at their lipid phase transition temperature, thus avoiding, or at least minimizing, chilling injury (Arav et al, 1996).…”

CRIOTOLERÂNCIA DE OÓCITOS E EMBRIÕES BOVINOS MATURADOS COM LÍQUIDO FOLICULAR E/Ou Β-Mercaptoetanol

“…Nos últimos anos, avanços importantes foram obtidos na metodologia de criopreservação de oócitos e embriões bovinos produzidos in vitro (PIV), como o nascimento de produtos derivados de oócitos vitrificados (1) e maior taxa de embriões provenientes de oócitos bovinos vitrificados com elevadas taxas de resfriamento e reaquecimento (2)(3)(4) . No entanto, os resultados da criopreservação ainda são pobres, possivelmente pelas diferenças decorrentes da produção in vitro em relação à produção in vivo.…”