Overview

The ddPCR five-site EGFR panel detects five of the most decision-driving EGFR alterations, including the T790M resistance mutation that frequently emerges during first-line tyrosine kinase inhibitor therapy. For B2B buyers serving thoracic oncology programs, the appeal is sensitivity: droplet digital PCR can report low-frequency variants from plasma when tissue re-biopsy is impractical. This article explains how the panel guides resistance management.

How It Works

The assay partitions each sample into thousands of droplets, amplifies target sequences with mutation-specific probes, and counts positive versus negative partitions. Because it is an absolute, endpoint measurement, it reliably quantifies a mutant fraction as low as a fraction of a percent. The five sites cover the common sensitizing changes and the major acquired-resistance change, so a single run can both confirm initial sensitivity and flag an emerging escape mutation.

Indications

The panel is indicated for EGFR-mutant non-small-cell lung cancer at progression on a prior inhibitor, where confirming T790M or another change determines the next line. It is also useful for baseline plasma testing when tissue is scarce. Buyers should present it as a monitoring and resistance tool, distinct from broad panel profiling, because its strength is precise quantification of known, clinically defined sites.

Dosage & Administration

Sample handling determines quality: plasma should be separated promptly and stored frozen before shipment; tissue nucleic acid follows standard extraction. Laboratories should define the limit of detection per site and the recommended sample volume. Results are reported as mutant copies per milliliter or as fractional abundance, with a clear call on whether a resistance mutation is present above the validated threshold.

Storage & Sourcing

Reagents require strict 2 to 8°C storage and protection from light, with cold-chain transport and temperature logging. Source from suppliers who provide lot-specific performance certificates, reference materials, and validated software. Confirm the menu covers all five sites on one cartridge and whether the platform shares consumables with other assays to simplify lab inventory planning.

Because the assay reports an absolute mutant count, laboratories should agree a retest rule with the clinician for samples that fall just below the validated reporting threshold, and should archive droplet data for audit if a result is challenged.

FAQ

Q: Why is T790M the key mutation this panel tracks at progression? Q: Can plasma testing replace a tissue re-biopsy for resistance confirmation? Q: What is the detection limit for low-frequency variants? Q: How are results expressed for clinical decision making?