Sequencing reading of TET1 gene from a whole 4-cell embryo and single blastomeres of a 4-cell embryo. (A) and (B): Clear sequence reading from two individual embryos at 4-cell stage. (C) and (D): Clear sequence reading from two individual blastomeres of a 4-cell stage embryo. (E) and (F): Major chromatogram peaks were completely matched to TET1 gene sequence although there were some baseline noises.