[Investigation of 5-bromo-2'-deoxyuridine labelling mice retinal progenitor cells]

BrdU (5-Bromo-2'-deoxyuridine) is usually used to label the mitotic cells as well as to trace reagent in cell transplation. However, BrdU could also exert some side effect on cellular biological characteristics upon inappropriate use. To explore the appropriate concentration of BrdU for labelling retinal progenitor cells (RPCs), we co-cultured Embryonic day (E) 17. 5 RPCs with different concentrations of BrdU, which were 0.2, 1, 5 and 10 micromol/L, respectively. After 48 hours, the RPCs were proliferation- or differentiation-cultured. Immunofluorescence was used to detect the BrdU-positive ratio and differentiation potential. Cell count was used to evaluate proliferation ability, and lactate dehydrogenase (LDH) release assay was used to monitor cytotoxicity. The results showed that 0.2 micromol/ L BrdU could not label RPCs clearly, while BrdU of 1, 5 or 10 micromol/L could label the RPCs with similar ratios. 1 micromol/L BrdU displayed no obvious cytotoxicity and showed no obvious effect on the proliferation and differentiation ability. However, 5 micromol/L or 10 micromol/L BrdU could evidently inhibit RPCs proliferation, partly due to the cytotoxicity effect. Furthermore, 10 micromol/L BrdU could inhibit the differentiation of RPCs towards MAP2-positive nerve cells, but showed no influence on the differentiation of RPCs towards GFAP- and glutamine synthetase positive glial cells. This study suggested that 1 micromol/L BrdU could be an appropriate concentration for RPCs labelling and could efficiently label RPCs without obvious side effect.