3. Intra- and Inter-run IHC Staining Variability
Intra-run variability occurs when IHC-stained slides, from the same processing run, exhibit notably different staining intensities, which are not deemed to be due to biological variance. This can be caused by incorrectly diluted reagents or machine failure resulting in inconsistent application of reagents.
Inter-run variability occurs when runs performed at different times or on different days result in variable staining across a series of slides or different studies. This variability can be caused by many factors such as issues with the automated IHC staining platform or not using identical batches of antibody or reagents.
When inter- and intra-run variability occurs, it can be challenging for image analysist scientists to make accurate comparisons between samples within or across studies.
Automated IHC staining platforms that include environmental controls and utilise standardised reagents can reduce potential intra- and inter-run variability.