Tetraploid complementation assays are used to examine the potency of a particular stem cell. Scientific studies in medical journals performed on chimeras (the mixture of cells of two distinct animals) revealed that the fusion of two embryos with eight cells resulted into cells containing four sets of chromosomes referred to as tetraploid cells, which are predisposed to developing into an extra-embryonic tissue, i.e., the placenta.
The embryo is not generated by the tetraploid cells; rather, it develops from the injected stem cells (diploid). This predisposition has been subjugated to examine a stem cell’s potency. The initial process involves the injection of stem cells into a tetraploid embryo. An embryo should develop if the injected stem cells happen to be pluripotent. Shall it yield a negative result, or should the ensuing embryo fail to endure until birth, then it means that the injected cells were not pluripotent.