Control Antibodies
Control antibodies are the vital part of assay design, this ensures the detected signals are attributed to specific antigen binding, rather than non-specific background staining. Control antibodies are commonly applied to determine background staining levels. Moreover, these antibodies can be utilized as the blocking agents before addition of primary antibodies. The common control antibodies including: loading control antibodies, isotype control antibodies.
Loading control antibodies
Loading control proteins are expressed constitutively and stably at high level in most tissue and cells. Housekeeping proteins represent some loading control proteins like: GAPDH, tubulin, actin.
Loading control are selected frequently from proteins expressed by the housekeeper genes. These controls can normalize the levels of protein of interest in confirming the same protein loading across the gel. The expression levels of the loading control are constant between different sample lanes. In addition, it is critical that the selected protein as the loading control should have different molecular weight with the protein of interest. In order to avoid overlapped staining and interference to the testing result.
The main functions of loading control antibodies in Western blotting:
- Estimate the relative amounts of total protein loaded in each lane. This information is required to determine different level of the protein of interest in different samples. Duo to landing and transfer errors, or alternatives in protein expression.
- Troubleshoot in the Western blotting procedures.
Feiyuebio provides antibodies against the most common loading control proteins, the loading control antibodies are helpful for assessing western blotting efficiency, and comparing the amounts of loading protein in each well across a gel.
Isotype control antibodies
The isotype control is an antibody as a negative control in antibody staining applications. Isotype control antibodies have the same isotype as primary antibodies, but no relevant specificity to the target antigen. These antibodies are applied as negative controls in the experiment of flow cytometry and tissue staining.
Isotype controls can distinguish specific antibody staining and background staining in experiments. In addition, these antibodies also can apply as a negative control to determine the blocking or washing steps in protocols.