Idylla MSI Assay (RUO)
A0101/6
Microsatellite instability (MSI) arises when the DNA mismatch repair (MMR) system fails to correct replication errors in short repetitive sequences, leading to the accumulation of mutations across the genome. MSI is an important molecular feature of two tumor types in particular: it is found in roughly 5-15% of colorectal cancers (CRC) and in an estimated 25-30% of endometrial cancers (EC)1. Because it connects hereditary cancer syndromes, tumor biology, and the immune microenvironment, MSI status has become a key parameter for researchers studying mutational burden, neoantigen formation, and response to immune checkpoint inhibition. Reliable, reproducible MSI detection therefore supports a wide range of clinical oncology research questions.
In MSI-high tumors, nucleotide shifts at microsatellite loci are often subtle and differ by tumor type (see Figure 1). Dedicated algorithms for endometrial and colorectal cancer therefore help ensure reliable MSI detection.
The Idylla™ MSI Assay provides a rapid, reliable solution that closes an important gap in oncology research by enabling MSI detection in endometrial and colorectal cancer in a single cartridge.
For Research Use Only (RUO), not for use in diagnostic procedures.
Awosika, J. A., Gulley, J. L., & Pastor, D. M. (2025). Deficient Mismatch Repair and Microsatellite Instability in Solid Tumors. International Journal of Molecular Sciences, 26(9), 4394. https://doi.org/10.3390/ijms26094394
Product Features
- Detection of mutations in 7 short homopolymer biomarkers (ACVR2A, BTBD7, DIDO1, MRE11, RYR3, SEC31A, and SULF2) that result from mismatch repair deficiency.
- Fully automated reporting of the microsatellite status: MSI-H when two or more biomarkers are mutated, and MSS when fewer than two are mutated.
- Tumor-specific MSI classification algorithm and sample input requirements using the same cartridge.
- On-demand and reliable MSI testing with low hands-on time (< 3 min), directly from FFPE tissue.
- No matched normal sample needed.
- A turnaround time of < 3 hours from FFPE tissue to result.
- Specimen requirements:
- 1x 5 μm FFPE tissue section: 50-600 mm²
- 1x 10 μm FFPE tissue section: 25-300 mm²
- CRC: Neoplastic cells ≥20% - if less, macrodissection is required
- EC: Neoplastic cells ≥40% - if less, macrodissection is required
TWO DISEASE STATES, ONE CARTRIDGE, EXCELLENT CONCORDANCE
Use the Idylla™ MSI Assay to accommodate reliable and easy MSI detection in CRC and EC. Two diseases, one cartridge and accurate MSI results in under 3 hours.
Endometrial Cancer
In a multinational 8-center study, the updated Idylla™ MSI Assay was compared with MMR status in 343 endometrial cancer samples with ≥ 40% neoplastic cell content
- 92% PPA versus dMMR (143/156)
- 97% NPA versus pMMR (183/189)
| dMMR | pMMR | Total | |
| Idylla™ MSI-H | 141 | 6 | 147 |
| Idylla™ MSS | 13 | 183 | 196 |
| Total | 154 | 189 | 343 |
Colorectal Cancer
In CRC, the Idylla™ MSI Assay demonstrated high concordance to IHC and a low invalid rate:
- 98% PPA versus dMMR (55/56)
- 97% NPA versus pMMR (184/189)
- 1.08% invalid rate
