The importance of oil for IVF outcome
Most clinics today use oil to cover embryo culture dishes in order to maintain stable temperature, osmolality and pH. The quality of such oil plays a very important role for IVF success. The oil types commonly used are mineral oil, paraffin oil or a mixture of both these oil types. This blog post lets you know the characteristics of the perfect oil for IVF.
Paraffin oil and mineral oil are chemically slightly different. The polycarbon lipid tail of mineral oil contains more unsaturated bonds than the more saturated paraffin oil. This makes mineral oil more unstable and prone to attack by free oxygen radicals and photo-oxidation than paraffin oil.
Paraffin oil gives better development
In a study by Tae et al.1 bovine embryo development was studied in cultures overlaid with either washed mineral or sterile paraffin oil, Fig 1. Sterile filtered paraffin oil overlay resulted in significantly higher (p < 0.05) development rate to morula (44.8% versus 30.6%) and blastocyst (32.8% versus 21.7%) than washed mineral oil.
Oil is not just oil
Oils from six different manufacturers were tested and embryo development and viability was evaluated2. Fig 2. OVOIL showed significantly better development (p<0.01) for all embryo viability parameters studied, number of cells in the trophectoderm and in the inner cell mass, and total number of cells in the blastocysts.
The importance of peroxide-free oil for embryo culture
Japanese researcher Otsuki and colleagues experienced reduction in fertilisation rate and impaired embryo development when they began to use a new bottle of oil at their IVF clinic. They decided to make an investigation of the root cause and found it to be high peroxide levels in the oil.
Download a summary of their findings to learn more about why high peroxide levels in oil can harm the culture system and the results from peroxide values in oil from different manufacturers.
REF: 1. Tae, J.C. et al. J. Assist Reprod & Gen. 2006 2. D. Linck, SIRT, Australia, 2008