Figure 2. Characterization of placenta-derived mesenchymal stem cells based on surface and nuclear markers expression from different maternal age group. (A) Representative histograms of detection by fluorescence-activated cell sorting (FACS) demonstrates positive expression of three MSC pluripotency intracellular markers. Populations are more than 95% positive for SSEA4 and NANOG. (B) Representative histograms of detection by FACS demonstrates positive expression of three MSC multipotency surface markers. Populations are more than 99% positive for CD90, CD73 and CD105. (C) Representative histograms showing no detection by FACS demonstrates no expression of the immunologic markers CD45 and CD3. Populations are more than 99% negative for CD45 and CD3. (D) Graphs of difference in mean fluorescence of MSC pluripotency intracellular markers of all 5 age groups. (E) Graphs of difference in mean fluorescence of MSC multipotency surface markers of all 5 age groups. (F) Graphs showing difference in expression of MSC pluripotency intracellular transcripts NANOG, OCT4 and SOX2 gene expression measure by Real Time PCR of all 5 age groups. Group A: 18-21; Group B: 22-25; Group C: 26-30; Group D: 31-35; Group E: 36 and over. *, p<0.05; **, p<0.01; ***, p<0.0005; ****, p<0.0001.