Epitope Tags Monoclonal Antibody-useful tools for fusion recombinant protein detection

Recombinant protein technology is one of the most widely used biotechnology to obtain target protein. Protein purification is the most critical and difficult step in recombinant protein technology. The quality of the target proteins depends on the step of purification. Currently, the conventional method is to fuse target protein and an affinity purification label (Tag), the target protein can be purified through affinity purification of the tag.

In addition, how to detect the expression of target protein is also a big problem for biologists. It is obviously complicated and expensive to use different antibodies to detect different target proteins. Sometimes it is even impossible to find an appropriate specific antibody against the target protein in the market. However, the problem will be solved if we have the antibody directed specifically against the tag. Furthermore, the monoclonal antibody against the tag will perform as “an secondary antibody”, that is to say, this antibody can be used to detect any protein with the same tag. Therefore, antibodies against the tag is a very useful tool for protein detection.

The commonly used tag includes Myc、HA、Flag、His、Gst, etc. His is the most widely used tag. His-Tag (HHHHHH), contains only six histidines , has no net charge at pH8.0. It is very small with almost no immunogenicity. Therefore, it is very difficult to prepare the antibodies against his-tag including monoclonal and polyclonal antibody so that it is difficult to get his-tag antibody of good quality in the market. If any, it is very expensive and imported from abroad.

Though we tried a lot of traditional methods for preparation of monoclonal antibody to His tag, all of them ended in failure. However, we developed special method and finally succeeded in preparing the antibody (Monoclonal Antibody to Hexa Histidine-Tag (H6)，MAX656Ge21). The antibody is very stable and has good specificity that it can be applied to detect different proteins fused with His-Tag.

His-tag antibody is applicable for intracellular localization, purification, qualitative detection and quantification of the proteins fused with His-tag. This antibody can be used to detect proteins fused with His-Tag at both of N-terminal and C-terminal. Currently, we Cloud-Clone Corp. have also developed antibodies against GST label.