HER3 Competitor Comparison Data
HER3/ErbB3 (D22C5) XP® Rabbit mAb #12708 performance was compared to competitor 1 HER3 mouse monoclonal antibody and competitor 2 HER3 rabbit monoclonal antibody. Antibody specificity, sensitivity, and consistency were evaluated in a number of cell lines and tissue samples using immunohistochemistry (IHC). All antibodies are approved for use in this application.
Highly Sensitive Antibody
HER3/ErbB3 (D22C5) XP® Rabbit mAb #12708 demonstrates a strong, specific signal in positively expressing cell lines, compared to IHC-approved HER3 antibodies from competitors 1 and 2. IHC analysis of paraffin-embedded MCF7 (HER3 positive) and MDA-MB-231 (HER3 negative) cells using #12708, competitor 1, or competitor 2. Optimal dilutions for each antibody were determined based on the point at which minimal signal was obtained in the negative cell line.
Cross-Reactivity with Other Family Members
HER3/ErbB3 (D22C5) XP® Rabbit mAb #12708 specifically detects HER3 and not other HER/ErbB family members. IHC analysis was performed in paraffin-embedded 293T cells transfected with the various HER/ErbB family members as indicated using #12708, competitor 1 or competitor 2. At the optimal dilution determined above, competitor 2 demonstrates non-specific staining in 293T cells. Further dilution of competitor 2 to eliminate the non-specific staining resulted in a weaker HER3 signal.
Consistent Performance Across Multiple Cell Types
HER3/ErbB3 (D22C5) XP® Rabbit mAb #12708 performs consistently in a wide range of cell types. IHC analysis of paraffin-embedded cell pellet arrays using #12708, competitor 1, or competitor 2. A total of 56 cell pellets were examined, and representative results from 5 cell lines are shown here. Only #12708 consistently displays a strong signal in HER3-positive cell lines. Although competitor 1 showed staining in appropriately expressing cell lines, the signal was overall weaker than #12708. Competitor 2 antibody showed inconsistent results and inappropriate localization of signal.
No Mouse on Mouse Cross Reactivity with a Rabbit Monoclonal Antibody
HER3/ErbB3 (D22C5) XP® Rabbit mAb #12708 demonstrates superior performance in mouse tissue. IHC analysis of paraffin-embedded HCC827 xenograft using #12708, competitor 1, or competitor 2. Rabbit mAb #12708 produces a specific signal with no background in mouse tissue. Competitor 1 has a weaker signal in the tumor as compared to #12708 and displays mouse-on-mouse staining, which is commonly seen with mouse monoclonal antibodies. Competitor 2 produced an inappropriate staining pattern, staining stroma not tumor.