1. Rescue of mouse embryos from 2-cell blocks by microinjection of maturation promoting factor 
Hideyuki Nakano, M.D., Ph.D., Harumi Kubo, M.D., Ph.D. 
Fertility and Sterility 
Volume 75, Issue 6, Pages (June 2001)
DOI: /S (01)

2. Figure 1
Microinjection of MPF into one of the blastomeres of 2-cell stage mouse embryos. Morphologically normal embryos were used for all study groups (A). Embryos were immobilized by the holding pipette in the 9 o’clock position, and the injection pipette was inserted in the 3 o’clock position through the zona pellucida deep into one of the blastomeres (B). The embryos were injected with 10–20 pL of MPF in mHTF medium under mineral oil (C). The arrow indicates the point where the injection pipette was inserted.
Nakano and Kubo. Rescue from mouse 2-cell block by MPF. Fertil Steril 2001.
Fertility and Sterility  , DOI: ( /S (01) )

3. Figure 2
In vitro development of 2-cell stage embryos after microinjection with MPF. One of the blastomeres of the 2-cell stage embryos was injected with MPF purified from Xenopus eggs (MI group) or mHTF medium (MED group). Numbers of injected oocytes are indicated in parentheses.
Nakano and Kubo. Rescue from mouse 2-cell block by MPF. Fertil Steril 2001.
Fertility and Sterility  , DOI: ( /S (01) )

4. Figure 3
In vitro development of 2-cell stage embryos at various times after microinjection with MPF. One of the blastomeres of the 2-cell stage embryos was injected with MPF purified from Xenopus eggs 24–28 hours (MI-Pre group), 28–32 hours (MI group), and 32–36 hours (MI-Post group) after insemination. Numbers of injected oocytes are indicated in parentheses.
Nakano and Kubo. Rescue from mouse 2-cell block by MPF. Fertil Steril 2001.
Fertility and Sterility  , DOI: ( /S (01) )