The impact of cumulus cell viability and pre-culture with the healthy cell mass on brilliant cresyl blue (BCB) staining assessment and meiotic competence of suboptimal porcine oocytes.

Objectives of the present study were to investigate the characteristics including glucose-6-phosphate dehydrogenase activity, as determined by Brilliant Cresyl Blue (BCB) staining, of suboptimal porcine oocytes and to enhance the meiotic competence of those through pre-culture with cumulus cell masses (CCMs). Percentage of oocyte-cumulus complexes (OCCs) derived from small follicles (SF; <3 mm in diameter) containing the oocytes that were assessed as BCB-negative (BCB-) was significantly higher than those derived from medium follicles (MF; 3-6 mm in diameter). Degrees of dead cumulus cells were significantly higher in OCCs containing BCB- oocytes, regardless of the origin of OCCs (MF vs.