Mononuclear cells was isolated from the buffy coat layer of the corb blood by the Ficoll-Paque layering assay. Cells were then cultured with erythrobalst differentiation medium. Single cell suspensions were collected at the respective time points and the live cells were enriched by Dead Cell Removal Kit (Miltenyi). The enriched cells were then harvested for STAR Scripts run using C1 Fluidigm Open App chips (10-17um). The open chromatin was transposed by Tn5 transposase. Cell specific barcode was integrated to tagmented DNA of each cell by PCR amplification with indexed primer. The amplified PCR produced was purified by Ampure XP beads and the purified ATACseq library was sent for sequencing.