Mouse Embryo Assay, MEA test is the legal requirement for release of new media batches, however, The Bovine Embryo Assay (BEA) test is an extremely important addition!

ARTSMedia Denmark’s media batches are regularly monitored through BEA tests which are also an important part of our Research and Development.

There are huge differences in reproductive physiology between the mouse and a woman, obviously also between a cow and a woman. The most obvious similarity in cow and woman is gestation time and that they don’t give birth to litters like mice.

However, the MEA test is considered sufficient for quality control release of ART media. When media are tested in the BEA, that all have passed MEA, they often give significantly different blastocyst rates as well as considerable morphologic and kinetic differences in the BEA test.

In vitro oocyte maturation (IVM), is at the moment not a standard procedure in human ART as it is and has been for decades in bovine ART. Therefore the BEA test includes quality control of all steps of the procedure, IVM, IVF and IVC.

In addition, fertilization and capacitation are species specific and a MEA test mostly assesses blastocyst development from either one-cell or two-cell stage embryos. Should a batch variation occur it will not be detected in a MEA test, where release parameter is > 80 % blastocyst rate. In the BEA test, however, a difference in medium quality can be detected even though the medium has passed the MEA test. For instance, 35 % vs 55 % blastocyst rates indicate two media are different, however both media will have passed the MEA. Hence, the MEA is a mere toxicological bio-assay, whereas the BEA also provides functional and performance data.

Therefore, we have decided that several batches will undergo the BEA test in addition to the required MEA Test.

How is the BEA test conducted?

Ovaries from slaughterhouse cows are collected, and in the laboratory the oocytes are aspirated from all follicles larger than 3 mm. Approximately 8 oocytes per ovary is on average obtained. They are subsequently matured, fertilized and cultured. The media are tested and blastocyst rates, kinetics and morphology are evaluated as well as hatching rates. The average blastocyst rates in the BEA test are between 40-50% and thus indicate performance differences, whereas 80 – 90 % blastocyst rates in the mouse embryo assay (MEA) test only indicate whether the medium is toxic or not.

Plastic vs Glass bottles

Only in glass bottles can you maintain stability of the active compounds in the media for up to 18-24 months. Plastic will decrease quality of media over time and even contribute to toxicity and will always have a limited shelf-life. The entire batch must be manufactured in one day. That means that no stock solutions should be stored for a longer period of time and that the entire batch should be manufactured and bottled within the same day and not stored overnight.

Batch Certificate

Every single batch is provided with a batch certificate stating that sterility, fungal and endotoxin tests have been performed and passed quality control specifications. 

For some products or batches the quality data may currently not be available on-line, to receive the certificate of analysis click here.

More similarities and differences

Based on:

Virtues and limitations of the preimplantation mouse embryo as a model system

Robert A Taft Theriogenology.

Read the full article here: https://doi.org/10.1016/j.theriogenology.2007.09.032

Or feel free to contact us