Evaluation and scoring of controls and calibrators are important in identifying potential immunostain problems. Unlike tissue sections, the analyte-coated microbeads in IHControls® and IHCalibrators stain comparatively homogeneously and do not require special training in histology for evaluation. Stain quality can easily be evaluated by histotechnologists.
Rim staining + : The majority of microbeads have accentuated rim staining. Compare the rim staining to the rims of unstained microbeads to appreciate the accentuation.
Central staining + : The majority of microbead centers are stained.
Helpful tip: The strongly stained microbeads are (on average) of equal or greater color intensity to the smaller color standard microbeads.
Rim staining +, but weaker: Rim staining is present, but less intensely. Rim staining can be appreciated by comparing to unstained microbeads.
Central staining +/– : The centers of many microbeads are tinted brown, but often not uniformly throughout the microbead interior.
Helpful tip: The moderately stained microbeads are of a mildly-moderately weaker intensity than the small color control microbeads.
Rim staining +/-: is barely detectable, which distinguishes stained microbeads from unstained beads.
Central staining –: The microbead interior appears washed out, without appreciable staining.
Helpful tip: The weakly stained microbeads are distinguishable from unstained microbeads, but the difference is subtle.