Patient Information/FAQs


Our patented Know Error DNA test protects you as a patient by comparing your reference DNA to the DNA of the biopsy specimen(s) used in your diagnosis to increase diagnostic accuracy by detecting and ruling out biopsy specimen switching and contamination errors.

The following patient information and resources are provided as a service to our patients, family and friends using or thinking about using the know error® system and/or Strand’s UroSeq® Hereditary DNA Repair Gene Panel testing. If you have questions or would like additional information please contact a client services representative Monday through Friday, 8:00 a.m. to 5:00 p.m. ET at 1-888-924-6779, option 2.


Know Error and who should get tested?

Commonly referred to as the Know Error DNA test, DNA Specimen Provenance Assay (DSPA) is a DNA fingerprint comparison of a patient’s reference swab to the biopsy tissue being evaluated for that patient. Incorporating Know Error into the diagnostic testing cycle for cancer increases diagnostic accuracy and confirms patient identity and specimen purity significantly reducing the opportunity for adverse outcomes due to Specimen Provenance Complications (SPCs), switching and contamination errors.

Anyone who’s had a biopsy or will have a biopsy. Whether you or a loved one has already had a biopsy or are scheduled for a biopsy, the staff at Strand Diagnostics can work with you and your doctor to confirm that your biopsy results actually belong to you and are free from contamination. Publications indicate that prostate and breast biopsy patients are at risk for misdiagnoses due to biopsy specimen switching errors or contamination (referred to as Specimen Provenance Complications, SPCs). There are up to 18 different steps in the diagnostic testing cycle from the time your biopsy specimen is taken until diagnosis. The patented know error® system increases both patient and practice safety, safeguarding you from undetected SPCs.

Why is the Know Error DNA test important?

Medical mistakes happen! One (1) in 30 patient’s biopsy samples get switched with another person or contaminated by another person according to medical journal studies. These studies indicate biopsy patients may be subject to undetected specimen transposition or contamination which could lead to a cancer diagnosis being assigned to the wrong patient. When this happens, patients with a false-positive diagnoses could receive unnecessary treatment, while patients with a false-negative diagnoses would not receive the care they need in a timely manner. Our patented know error® system along with our DNA Specimen Provenance Assay (DSPA) test protects patients by comparing the DNA of a reference sample to the DNA of the biopsy tissue(s) used in  the diagnosis to detect and rule out biopsy specimen switching and contamination errors.


Pfeifer JD, Liu J. Rate of occult specimen provenance complications in routine clinical practice. Am J Clin Path. 2013;139(1):93-100.

Why do you need my DNA?

Your DNA plays an important part in the biopsy evaluation process. With a reference sample of DNA (taken via cheek swab at the time of your procedure), physicians using the know error® system can confirm that any biopsy samples used in your diagnosis are, in fact, your samples and are free from contamination.

Will my DNA information be kept confidential?

Your DNA will ONLY be used for the Know Error test or other tests ordered by your doctor (i.e. Strand’s UroSeq® hereditary DNA repair gene panel for prostate patients). Further, all of your personal information is protected by the Health Insurance Portability and Accountability Act (HIPAA). To review our comprehensive privacy policy, please refer to

What is self-identification?

Self-identification is your part in the know error® system. Your initials next to your name and patient information on the cheek swab bag label is the first step to ensure that you are you.

Does medical insurance cover the cost of DNA Specimen Provenance Assay (DSPA)?

We are here to answer any questions you may have regarding the know error® system and the Strand Diagnostics billing process. We can be reached Monday through Friday, 8:00 a.m. to 5:00 p.m. ET at 1-888-924-6779, option 1 or by email.

In general each insurance plan is different but many insurance companies will cover the cost of DNA Specimen Provenance Assay (DSPA). Strand Diagnostics is an out-of-network laboratory which allows Strand to work directly with a patient to limit out-of-pocket expenses.

Strand Diagnostics bills your insurance companies directly for you. Once your insurance company is billed, you should receive an EOB (explanation of benefits) from your insurance carrier. This EOB will explain how they have processed your charges and it may mention a “Patient Responsibility” portion. Please disregard that amount because their EOB is not the same as Strand’s bill. Strand Diagnostics will not bill you for any more than $295. If needed, Strand will work with you to establish a payment plan that works for you

There is a chance your insurance company will mail a check directly to you as reimbursement for the cost of Know Error testing. Please do not cash the check; instead contact Strand at 1-888-924-6779, option 1 (Monday through Friday, 8:00 a.m. to 5:00 p.m. ET) for information on forwarding the insurance check to Strand Diagnostics.

If you do not have insurance the uninsured price for a Know Error DNA test is $295. Self-pay patients may be eligible for a payment program tailored specifically for you. One of our patient financial services representatives can assist you Monday through Friday, 8:00 a.m. to 5:00 p.m. ET at 1-888-924-6779, option 1.

What is the Know Error procedure?
  1. At the time of your biopsy a DNA reference swab similar to a Q®Tip is gently rubbed inside your cheek by a medical professional. The swab is then sent to Strand Diagnostics for analysis.

  2. Your biopsy tissue sample(s) are placed in bar-coded specimen containers included in the Know Error biopsy kit and sent to the pathology lab for evaluation.

  3. If the biopsy results are positive for cancer (malignant) a small piece of the tissue is sent to Strand Diagnostics, where a DNA Specimen Provenance Assay (DSPA) 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 belongs to the ascribed patient and rules out the possibility of specimen contamination.

Once the DNA test is completed, an electronic report is sent to your physician for review. When necessary your physician will contact to you discuss your results.

Can I order the Know Error DNA test on my own?

For residents of many states you may order the Know Error DNA Specimen Provenance Assay without a doctor’s order. Just call one of our client services representatives at 1-888-924-6779, and select option 2 (Monday through Friday 8:00a.m. – 5:00p.m. ET.)

UroSeq® Hereditary DNA Repair Gene Panel and who should be tested?

Strand’s UroSeq® Hereditary DNA Repair gene panel testing includes includes BRCA1, BRCA2, ATM, CHEK2, HOXB13, PALB2 and RAD51D and the Lynch Syndrome genes MLH1, MSH2, MSH6, PMS2, and EPCAM. These are the genes the cancer guidelines recommend be tested for those patients diagnosed with prostate cancer. The test can be completed with a saliva sample collected in the convenience of your home or your physician’s office. If your physician uses the know error® system your sample has already been collected at the time of your biopsy.

Patients should be tested if:

  • A Gleason score of 8, 9 or 10
  • Have metastatic prostate cancer
  • A Gleason score of 6 or 7 AND
      • A strong family history of prostate cancer (defined as: brother or father or multiple family members who were diagnosed with prostate cancer at less than 60 years of age or who died from prostate cancer), OR
      • Ashkenazi Jewish ancestry, OR
      • Three (3) cancers on same side of family (especially those diagnosed ≤50 years of age diagnosed with bile duct, breast, colorectal, endometrial, gastric, kidney, melanoma, ovarian, pancreatic, prostate, small bowel, or uretheral cancer)
What are the clinical implications of a pathogenic hereditary DNA repair gene mutation?

There are four main implications for a pathogenic mutation:

  1. Patients are more likely to have aggressive disease and progress or recur more quickly
  2. Patients are at greater risk of additional primary cancers
  3. Patients may respond to PARP inhibitors
  4. Family member of patients with pathogenic mutations are at increased risk of cancer

If your UroSeq® test is positive for a gene mutation, your physician and Strand Diagnostics will arrange for a complimentary consultation with a certified genetic counselor. During this consultation additional information will be provided and all of your questions will be addressed.

Will my insurance company cover hereditary DNA repair gene testing?

Strand Diagnostics will bill your insurance company for your UroSeq Hereditary DNA Repair Gene Panel test. Many insurance companies cover this type of testing. Once your insurance company is billed, you should receive an Explanation of Benefits (EOB) from your insurance carrier–this is not a bill. This EOB will explain how they have processed your charges and it may mention a “Patient Responsibility” portion. Please disregard that amount because their EOB is not the same as a bill from Strand Diagnostics. If your insurance company does not approve the claim for testing the maximum out-of pocket expense is $95. If you have any billing related questions, contact our patient billing financial specialists at: 888-924-6779, option 1, Monday through Friday, 8:00 a.m. to 5:00 p.m. ET. If needed, Strand will work with you to establish a payment plan that works for you.

Other Strand Diagnostics billing questions?

Please contact one of our financial services representatives at 1-888-924-6779, option 1, Monday through Friday, 8:00 a.m. to 5:00 p.m. ET or by email and include your question(s) in the message.