In the case of antibody-based experiments, pre-immune IgG is used as a negative control to assess nonspecific reactions (isotype control). In western blotting, the detection of a housekeeping protein is used as a positive control for validation (loading control). Fujifilm Wako offers a lineup of products including isotype control antibodies and loading control antibodies.
Isotype Control Antibodies
Isotype control antibodies are used as a negative control for an antibody used in an experiment. By using isotype control antibodies, it is possible to determine whether the signal obtained by immunostaining or flow cytometry is derived from a specific antigen-antibody reaction or from nonspecific binding of the antibody to a protein other than the target antigen.
For the isotype control antibody, an antibody of the same animal species, same isotype, and labeled with the same enzyme as the antibody used to detect the target antigen in the experiment should be selected.
|Experimental Antibody||Isotype Control Antibody||Assessment|
|＋||－||The target antigen is specifically detected.|
|＋||＋||Highly likely that other antigens are also detected. (Non-specific signal is detected.)|
Loading Control Antibodies
Loading control antibodies are used in western blotting to confirm the consistency of sample processing and to compare protein levels between samples. Usually, antibodies to detect housekeeping proteins are used as loading control.
Housekeeping proteins including β-actin, α-tubulin, β-tubulin, and GAPDH (glyceraldehyde-3-phosphate dehydrogenase) are used as a target of loading control antibodies . Although these proteins are stably expressed in most cells, their expression can increase or decrease depending on the conditions. It is necessary to select a loading control antibody appropriate for the experimental system.
For research use or further manufacturing use only. Not for use in diagnostic procedures.
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