1. Microinjection of mitochondria into zygotes creates a model for studying the inheritance of mitochondrial DNA during preimplantation development 
Paolo Rinaudo, M.D., Tracy Niven-Fairchild, Syam Buradagunta, B.A., Marco Massobrio, M.D., Alberto Revelli, M.D., David L Keefe, M.D. 
Fertility and Sterility 
Volume 71, Issue 5, Pages (May 1999)
DOI: /S (99)

2. FIGURE 1
Illustration of the Hiramoto microinjection technique. A mouse zygote is being injected with fractionated mitochondria. The drop seen in the zygote cytoplasm is inert dimethylpolysiloxane (silicone oil), and the estimated volume is 1.8 pl. The same amount of release buffer containing mitochondria is injected into the zygotes. The drop of silicone oil seen in the zygote cytoplasm allowed quantification of the injection volume. Injection volume thus was standardized across all study groups. Original magnification, ×200.
Fertility and Sterility  , DOI: ( /S (99) )

3. FIGURE 2
Representative demonstration of the structural integrity of MELAS mitochondria after fractionation. Original magnification, ×15,000. Bar = 1 μm.
Fertility and Sterility  , DOI: ( /S (99) )

4. FIGURE 3
Representative demonstration of the survival of the MELAS mutation at least until the hatched blastocyst stage of development. The MELAS mutation derived from mitochondria, injected at the zygote stage, survived at least through the hatched embryo stage, as determined by PCR followed by restriction digestion. Uninjected and wild-type–injected embryos did not have detectable levels of the MELAS mutation. Lanes 1 and 2 are uninjected controls. Lanes 3 and 4 are controls injected with wild-type mitochondria. Lanes 5 and 6 show the MELAS mutation still present in the blastocysts that were injected at the zygote stage with MELAS mitochondria. Of the injected embryos, only lane 10 exhibited no MELAS mutation, although this zygote had been injected with MELAS mitochondria. bp = base pairs.
Fertility and Sterility  , DOI: ( /S (99) )

5. FIGURE 4
Survival of embryos that were injected with MELAS or wild-type mitochondria and control embryos that were not injected or were sham-injected with release buffer. The embryos were analyzed for 4 days after injection. Day 1 was the day of injection. There was no difference in survival between the groups.
Fertility and Sterility  , DOI: ( /S (99) )