NTC Samples QC

The VeriSeq NIPT Solution allows the addition of NTC samples as part of the run. The ML STAR can generate up to 2 NTCs per run for 24-sample and 48-sample batches and up to 4 NTCs for 96-sample batches. Regardless of how many NTC samples are added, the software checks for a minimum average of 4,000,000 unique mapped fragments per sample per pool. For this reason, do not add more than two NTC samples per pool. For more information, refer to Sequencing QC Metrics and Boundaries.

QC statuses for NTC samples are as follows.

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NTC sample processing—When processing an NTC sample, the software applies a PASS QC result when coverage for the sample is low, as expected for NTC.

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Patient sample as NTC—When a patient sample, marked as NTC, is processed, high coverage is detected. Because the sample is marked as NTC, the software flags the sample QC status as FAIL with the following reason: NTC SAMPLE WITH HIGH COVERAGE.