Application / Activity

1. Why are some proteins fused to tags?

The initial use of protein tags is for protein purification purpose. In addition, tags are also used for protein detection in several applications, such as western blot and ELISA, when the specific antibodies are not available. Furthermore, Fc tag stabilizes molecules, which may increase the half-life of the linked products. Since the Fc fragment tends to dimerize, it helps the linked protein, particularly receptors, to form biologically active dimers. SBI also has human IgG1 Fc region (10702-HNAH ) and mouse IgG1 Fc region (10690-MNAH ) for purchase as a control.

2. Do protein tags affect protein activity?

It is different from case to case. For some applications, small tags, such as His tag and Flag tag, may not affect protein activity and do not need to be removed. For example, there are more than 100 structures of His-tagged proteins in the Protein Data Bank. This indicates that the small His-tag often do not interfere with correct protein folding. Additionally, tested activity results are listed on our protein web pages, if you have concerns about tags interfering with protein activity. If there is no activity data online and activity is crucial to your experiments, please feel free to contact us (order@sinobiological.com) for latest information. For some recombinant proteins from SBI, fusion tags are removable by proteases. Please contact us for details.

3. Can SBI products be used for other applications which are not listed on SBI Certificate of Analysis?

If a specific application is not listed in SBI Certificate of Analysis and not tested by SBI yet, please send us your requirements to order@sinobiological.com. We will check if we could perform the assay or if any published data of the same product and the same application are available.