Tris-Tricine system is generally used. The common Bio-Rad system can separate protein as small as 1 kDa, but it is powerless for protein over 250 kDa. It is sold separately by pieces, and the price of each piece is around 130, which is expensive. However, it is acceptable to buy a beautiful electrophoregram once in a while and use it to send papers. The EZBiolab-Tricine glue of Wansheng Haotian Bio can separate protein as small as 3kDa, but it can't do anything for protein over 250kDa, and the price is relatively cheap, about 100 per tablet. However, the shelf life of Tris-Tricine is generally short, about one month.