mRNA expression of transcription factors.

Flk-1⁺ VE cadherin⁻ cells, GFP⁻VE cadherin⁺ CD45⁻Ter119⁻ cells, and GFP⁺ VE cadherin⁺CD45⁻Ter119⁻ cells were induced in vitro from ES cell-derived Flk-1⁺ cells for 2.5 days, and different dilutions of cDNA prepared from sorted cells were subjected to PCR amplification using primers specific for Runx1, SCL, c-Myb, GATA-2, and β-actin. PCR products were separated on 1% agarose gel and stained with ethidium bromide. The results shown are representative of 3 independent experiments.