BEAVER TCT Bottles adopt unique structure design (patent No. :ZL201320051575.7), avoid dead Angle and step in cell culture bottle, help culture medium or cell suspension pour smoothly, and will not cause cell residual loss and cell pollution. In addition, double thread design of the asymmetrical zigzag bottle neck is beneficial to decreasing more smooth cap rotation, better self-locking ability, easier tightening and loosening operation. After the cap is tightened, it shows high sealing performance, which greatly reduces the probability of cell contamination.