Detection of hMSCs at different timepoints after IV injection. Different tissues/organs were collected at various timepoints (day 1 (D1) and 7 (D7); n = 3) after the infusion of hMSCs. RNA was extracted from these tissues and analysed by RT-PCR. Human-specific CD90 (hCD90) and GAPDH mRNA expression were detected by electrophoresis in a 2% agarose gel (hCD90 product size: 139 bp, GAPDH product size: 170 bp). bp, base pair; hMSCs, human mesenchymal stem cells; IV, intravenous; RT-PCR, reverse-transcriptase polymerase chain reaction.