Internal reference is internal control, for mammals (mammals; Mammalian cell expression usually refers to housekeeping proteins encoded and expressed by housekeeping genes. Their expression in various tissues and cells is relatively constant, and it is often used as a reference when detecting the change of protein expression level.

In the protein blot experiment, the test results of internal reference in the sample can be used to correct the experimental errors in the process of protein quantification and loading, thus ensuring the accuracy of the experimental results.