HER2 Gastric 4-in-1 FFPE Ref Std

Product Overview

The HER2 Gastric 4-in-1 FFPE Ref Std is a comprehensive reference material designed for validating human epidermal growth factor receptor 2 (HER2) detection workflows in gastric cancer diagnostics. This unique standard combines four distinct HER2 expression and amplification states in a single formalin-fixed, paraffin-embedded (FFPE) block, mimicking the full spectrum of clinical specimens encountered in routine testing. Manufactured using a proprietary fixation protocol that preserves both protein epitopes and nucleic acids, it serves as an essential quality control tool for laboratories performing HER2 testing to guide trastuzumab therapy decisions in gastric adenocarcinoma .

Product Features

Multi-State Validation

Contains four distinct HER2 phenotypes in spatially separated cores:

• HER2 0 (negative): <10% immunoreactivity, no amplification

• HER2 1+ (equivocal): weak incomplete membranous staining in ≥10% of cells

• HER2 2+ (equivocal): moderate complete membranous staining in ≥10% of cells

• HER2 3+ (positive): strong complete membranous staining in ≥10% of cells

Each state is verified by both immunohistochemistry (IHC) and in situ hybridization (ISH) .

FFPE Matrix Authenticity

Processed using 10% neutral buffered formalin fixation (24-hour protocol) and optimized paraffin embedding, the standard maintains histological integrity identical to clinical gastric cancer specimens. This preserves tissue architecture and biomarker expression critical for accurate HER2 assessment .

Quantitative Validation Metrics

Each core contains a known number of cells (5 x 10⁴ cells/core) with verified HER2 gene copy number (GCN) ranging from 1.8 to 8.2 copies/cell, enabling quantitative validation of ISH assays. GCN is confirmed by digital droplet PCR (ddPCR) with coefficient of variation <5% .

Usage

Section Preparation

Section the FFPE block at 4 μm thickness using standard microtomy techniques. Collect 3 consecutive sections per slide to ensure sufficient material for both IHC and ISH testing. Deparaffinize using xylene or xylene-free alternatives followed by ethanol rehydration.

IHC Validation Protocol

Use for validation of HER2 IHC staining protocols by:

• Verifying antibody specificity across expression levels

• Optimizing antigen retrieval conditions (recommended: 95°C in citrate buffer pH 6.0 for 20 minutes)

• Establishing scoring thresholds for each intensity category

• Monitoring staining consistency between reagent lots

ISH Validation Application

Validate HER2 amplification assays by:

• Confirming probe hybridization efficiency

• Verifying signal-to-noise ratios across GCN ranges

• Calibrating HER2/chromosome 17 ratio calculations

• Ensuring proper distinction between amplified and non-amplified states

FAQ

Why is a 4-in-1 format advantageous for HER2 testing?

The combined format allows simultaneous validation of all critical interpretation thresholds in a single run, reducing inter-assay variability and enabling direct comparison between expression states—essential for accurate equivocal case classification .

How does this standard support regulatory compliance?

It facilitates compliance with CAP HER2 testing requirements by providing traceable reference values for both IHC and ISH methods. Comprehensive documentation includes digital images of stained sections and quantitative PCR data .

Can it be used for training purposes?

Yes, the clear distinction between expression states makes it ideal for training laboratory personnel in HER2 scoring criteria, particularly for distinguishing between 1+, 2+, and 3+ categories .

What is the recommended storage condition?

Store unopened blocks at 4°C in a desiccator for up to 36 months. Once sectioned, remaining blocks should be wrapped in paraffin film and stored at 4°C, with sections used within 1 month of cutting .

Technical Data

IHC staining results