Abstract
The efficacy of a water purification system including a high-intensity 185 nm ultra violet lamp with ultrafilter (UV-UF) for eliminating endotoxins was examined. The activity of endotoxins was below the detectable level in UV-UF water. In contrast, ultra-purified water from a system without a UV lamp (UP) showed a high level of endotoxins, despite water resistivity of more than 18 MΩ·cm. Bovine IVM/IVF zygotes were cultured for 174 h in protein-free media prepared with UV-UF and UP water. The developmental rate to blastocysts at 150 h was significantly higher in the medium prepared with UV-UF water. The results demonstrate that the UV-UF system is beneficial for eliminating endotoxins from ultra-purified water, and for preparing protein-free media for culture of bovine embryos.
