As an unique social activity of human being, it includes subject, object and medium.
作为人类特有的社会活动，它包含主体、客体和中介三个要素。
2
The activity of lactic dehydrogenase in the tissue culture medium was measured by a LDH kit.
使用乳酸脱氢酶试剂盒，测量组织培养液中乳酸脱氢酶活性的动态变化。
3
Objective: To find out a method of extraction and purification of bone morphogenetic protein (BMP) from osteosarcoma cell conditioned medium, and evaluate the biological activity of BMP.