[Biological stability analysis of QY1 pluripotential mesenchymal stem cell line from Sprague Dawley rat bone marrow]

To explore the optimal culture conditions in vitro and the biological characterizations of the QY1 pluripotential mesenchymal stem cell (MSC) line from Sprague-Dawley rat bone marrow and to analyze the biological stability of this MSC line so as to provide an ideal cell model for the further differentiation and actual application.

The methods and technologies of cell biology and stem cell tissue engineering were used to purify MSCs. We determined the effects of morphology of cell proliferation, the time of change medium, growth curves, doubling time, adhesive rates, chromosome, culture conditions, and repeated frost on the biological characterizations of MSCs.

The cells had a fibroblastic-like morphology and were well spread out; 80% - 90% cells became confluent between 10 and 12 days in primary culture. The growth curves of Passage 1, 3, 10, and 20 were quite similar (P>0.05). The doubling time of passage 1, 3, 10, and 20 were 34.2, 33.9, 31.8, and 30.6 hours, respectively. The adhesive rates of Passage 1, 3, 10, and 20 were very much similar (P>0.05) and about 89% subcultured cells adhered to the wall in 10 hours. The most appropriate concentration of serum was 20% and the most appropriate concentration of cell number was 8 x 10(4)/mL. The cells of Passage 8 showed light red cytoplasm and heavy blue nuclear stained by Giemsa staining. The chromosomes of Passage 8 and 20 were normal in appearance and their karyotypes were 42, XY. The cells were resuscitable after repeated frozen, and more than 85% cells were alive. The cells had been continuously cultured for more than 10 months so far.

The QY1 MSCs line from Sprague-Dawley rat bone marrow is a purified cell line, which can maintain its undifferentiation and the stable biological characterizations for the long term.