RESUMO
AIM: To study the method of using BRL conditioned medium in ES cells culture. METHODS: ES cells were cultured in BRL conditioned medium, MEF feeder layer, and BRL conditioned medium plus MEF feeder layer respectively. Both the numbers of ES cells and embryonic bodies and the differentiated cells around the ES cell colonies at certain stages were studied to find the differences of growing speed of ES cells in three culture mediums. RESULTS: On promoting the growth and maintaining the undifferentiated state of ES cells at the early stage after recovery, the effects of BRL conditioned medium were less than those of MEF feeder layer and those of BRL conditioned medium plus MEF feeder layer (P < 0.01), and there was no difference between MEF feeder layer and BRL conditioned medium plus MEF feeder layer (P > 0.05). CONCLUSION: ES cells should be cultivated on MEF feeder layer or in BRL conditioned medium plus MEF feeder layer at the early stage after recovering.