Know Error

In using the latest applications of cutting-edge forensic DNA science, Strand Diagnostics provides DNA Specimen Provenance Assay (DSPA) testing though the patented know error® system. The know error system utilizes forensic principles, unique patient bar coding, and DSPA testing to increase diagnostic accuracy confirming that surgical biopsy samples being evaluated are free from contamination and belong exclusively to the correct patient. DSPA is a DNA fingerprint comparison of a patient’s reference swab to the biopsy specimen being evaluated for that patient. Incorporating Know Error into the diagnostic testing cycle for cancer significantly reduces the opportunity for adverse outcomes due to Specimen Provenance Complications (SPCs), switching and contamination errors.

Know Error can be easily integrated within an existing routine clinical process, regardless of whether pathology services are performed in house or by a reference lab partner. DSPA testing, as part of the know error system, is the standard of care to complete the diagnostic testing cycle for cancer, providing patients and physicians with a complete diagnosis to proceed with the personalized therapy for the appropriate patient.



How it works


Swab1. Swab

Before the biopsy procedure, a reference sample of DNA is taken by swabbing the inside of the patient’s cheek. The swab is then sent to Strand Diagnostics.

Sample2. Sample

The patient’s biopsy specimen sample(s) are placed in bar-coded specimen containers included in the biopsy kit and sent to the pathology lab for evaluation.

DSPA3. DNA Match

If the biopsy results come back positive for cancer (malignant) a small piece of the tissue (or unstained slide) is sent to Strand Diagnostics, where a DNA test compares the (1) swab reference sample to the (2) biopsy tissue sample(s) to assure a (3) DNA match and the sample purity. The DNA match confirms the diagnosis matches the DNA of the reference sample identified as belonging to the patient and rules out specimen contamination.

Once the DSPA is completed, an electronic report (compatible with most EMR systems) is issued to summarize the findings. The turn-around-time (TAT) varies depending upon the specimen type, but reports are usually issued within 5 – 6 calendar days after receipt of both the swab/reference and tissue sample(s). If a potential non-match is indicated, the appropriate parties are notified immediately to address the issue.


The know error system

  • Confirms specimen purity and brings diagnostic accuracy to a higher level
  • Exceeds patient and practice safety standards
  • Easily integrated into an existing clinical biopsy process
  • Biopsy collection kits are provided at no charge


More information about the patented know error system is available on our Know Error website.