System QC is usually an antibody that has been tested and stains every time under the identical conditions of which the patient tissue has been subjected to.
An example of a good system control antibody is vimentin. Vimentin is the most commonly used antibody for a system control. Using a system control such as vimentin provides a visual account of the staining methodology (manual or an automated system) and whether or not it is working properly. One drawback to using a system quality control is the creation of extra slides:
- One of a known positive tissue
- One slide you incubate using the vimentin
- Two slides for negative (one for negative control reagent and the other for negative tissue control)
