The composition of GEM is based on the results of experiments designed to determine the most supportive in vitro conditions for assisted reproduction and embryo manipulation. GEM is a chemically-defined, protein-free, embryo culture medium.
Investigators creating transgenic mice can be assured that culturing gene-injected zygotes in GEM provides the best in vitro conditions known for the support of post-implantation fetal development following transfer. Moreover, since GEM by-passes the “two-cell block”, injected embryos can be cultured to the four-cell stage before transfer, thus broadening the transfer window to accommodate fluctuations in the supply of pseudopregnant recipients.
GEM can be used as bottled, without protein supplementation, for zygote culture. If the surface tension of protein-free medium creates problems with embryo manipulations, it can be supplemented with bovine serum albumin (BSA) at levels as low as 10 ug/ml or as high as 4 mg/m It is recommended that BSA be added from a freshly prepared, filter sterilized stock solution in an aliquot of GEM for each embryo culture experiment, and that culture dishes be set-up for equilibration in the CO2 incubator five to 15 hours before use.
Mouse embryos develop best at 37oC in pH values 7.1 to 7.3, corresponsing to CO2 gas phase in the range of 6.5 to 8.5% (v/v), depending upon incubator conditions. GEM is one-cell mouse embryo tested in 0.8 to 1 ml cultures inl. a variety of culture vessels: organ culture dishes, multi-well plates or culture tubes. Embryos develop to blastocysts at the same rate whether cultured singly or in groups; microdrop culture of embryos in GEM under oil has not been found to improve zygote to blastocyst development, and because of the amino acid content, GEM is not recommended for microdrop culture under oil for more than 48 hours.
GEM is manufactured in small lots to insure the highest product quality and stability.
Discounts available for standing orders.
GEM is not approved by the US Food and Drug Administration for use in humans.
GEM is available in 40 ml and 60 ml bottles. It is prepared, filter sterilized, bottled and individually wrapped in a sterile environment.