O-STANDARDS™ are paraffin blocks of formalin-fixed and paraffin-embedded cells containing known amount of specific proteins. When used with OTMIAS®, these external standards are required for determining the proliferative activity, percentage of apoptotic cells, and for quantitative biomarker analysis..
Test samples must be prepared the way O-STANDARDS™ are prepared for optimal results.
Each biomarker O-Standard paraffin block includes one core of a positive cell line (example top figure on right) and one core of a negative cell line (example bottom figure on right).
1) Loss of antigenicity in cells and tissues usually starts the moment sections are cut. You can always cut fresh control slides from paraffin blocks, at the same time you cut your test samples.
2) The intensity of IHC staining is influenced by the thickness of the tissue sections. Cutting sections of standard blocks with test blocks at the same time on the same microtome minimizes difference in section thickness.
3) The influence of batch to batch variation in antigen expression in standard cell lines is eliminated by calibrating new batch values to the original O-STANDARDS™.
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