Analytical Validation of a Highly Quantitative, Sensitive, Accurate, and Reproducible Assay (HERmark^®) for the Measurement of HER2 Total Protein and HER2 Homodimers in FFPE Breast Cancer Tumor Specimens

Table 3

H2T and H2D assay validation summary. The parameters tested in the validation of the HERmark assay are summarized and the percentage passing is based on a 2-fold cutoff. NA indicates that a detailed pairwise comparison was not necessary and so therefore the 2-fold cutoff was not applicable. 195th percentile at 2.2 fold cutoff.

Parameter	H2T Summary	% Within Two-fold Cutoff	H2D Summary	% Within Two-fold Cutoff
Accuracy	Pass	NA (100)	Pass	NA (100)
Sensitivity	Pass	NA (100)	Pass	NA (100)
Precision	Pass	100	Pass	99.5
Reproducibility	Pass	96.4	Pass	91.8^1
Linearity: CE	Pass	99.7	Pass	99%
Linearity: Section Size	Pass	100	Pass	92.2^1
Specificity: Triple Re-embed	Pass	97.1	Pass	94.6
Specificity: Isotype	Pass	NA (100)	Pass	NA (99.1)