Table 2.

Flow cytometry results of low-passage and high-passage bone marrow mesenchymal stem cells

	Low passage (%)	High passage (%)
SCA1	14.3	74.4
CD45	3.0	4.7
SSEA4	2.2	95.5
MHC class I	3.7	4.0
MHC class II	2.7	4.4

An increase in the number of cells positively expressing SCA1 was observed as the passage number increased. An increase in the stem cell marker SSEA4 was also observed as the cell passage increased. Expression levels of CD45, MHC class I, and MHC class II remained relatively stable as the passage number increased. MHC, major histocompatibility complex.