Tips are certified sterile , dnase - , rnase - , and pyrogen-free to prevent sample contamination .
吸头经过消毒，无脱氧核糖核酸酶，无核糖核酸酶，无热原，可防止样本受到污染。
Tissue culture plates are normally sterile , while other plates will be rnase and dnase free .
组织培养板通常是无菌的，而其他板块将酶和酶自由。
Methods testicular sertoli cells from2to3-week-old male wistar rats were prepared by digestion with collagenase , trypsin and dnase and cultured together with active lymphocytes to observe their killing effect against lymphocytes .
