Between 2005 an 2011 the APB used the same IVF technique to re-animate strains from the frozen sperm archive. While the IVF efficiency for strains on BALB/c, CBA and mixed backgrounds was reasonable, the IVF efficiency for strains on 129 and C57BL/6 background were poor.

Throughout the world IVF laboratories struggled with fertilisation efficiencies with strains on C57BL/6 and 129 backgrounds.







In 2011, Professor Naomi Nakagata an his team published a manuscript describing advancements in C57BL/6 IVF. This was achieved through the addition of glutamine to the cryoprotectant, the addition of MBCD to the sperm capacitation media and GSH to the sperm / oocyte incubation media.

As can be seen from the graphs, incorporating the advances made by Nakagata into the APB procedure resulted in an increase in 2-cell efficiency to 80-90%.

The circled bars indicate the same strains subjected to both the old and new IVF procedures.