The importance of water quality for media preparation

The variability in pregnancy rates achieved among in-vitro fertilization (IVF) clinics may be partially attributable to the disparate quality of the water used in the preparation of culture media. The removal of contaminants in the water is of paramount importance since water constitutes the predominant component in any media formulation. To assist in the selection, operation and maintenance of a water purification system, the level of contaminants must be carefully monitored. Conductivity and resistance are used to measure the purity of natural and ultrapure water respectively. Feed water is analysed by an assortment of direct chemical means to determine the necessary system filtration steps. In general, high quality water can be produced by combined reverse osmosis and electrodeionization of treated tap water. Processed water is supplied to an ultrapure water system to provide final polished water. A detailed water processing protocol is presented along with quality assurance guidelines to ensure the consistent production of high quality ultrapure water suitable for in-vitro human embryo culture.