This is a companion article to the feature, “Developing and Marketing an FDA-Regulated Test.”
Cologuard is designed to be patient- and physician-friendly, and is highly automated to support efficiencies in Exact’s lab.
First, a physician orders the test and a collection kit is sent to the patient’s home. The patient collects a stool sample at his or her convenience—no medication, dietary restrictions, bowel preparation, sedation, time off work, or transportation is required. Once the collection is complete, the patient ships the kit directly to Exact’s lab in Madison, Wis, using a prepaid UPS mailer.
The lab where all Cologuard tests are processed is a 30,000 square foot, state-of-the-art facility certified under the requirements of the Clinical Laboratory Improvement Amendments of 1988 (CLIA). The facility is capable of scaling to perform up to 1 million tests per year.
Once returned, every sample goes through a multistep process:
- The sample is received at the lab.
- The kit is unloaded, opened, and assigned a unique identification number.
- A tube containing the fecal hemoglobin sample is separated from the bucket containing the stool sample and mixed, racked, and stored separately.
- The primary sample is weighed, shaken with buffer to make it uniform, and distributed into three tubes (one for testing and two for backup).
- The sample is frozen and thawed, a process that allows the lab to extract more DNA out of the sample.
- The sample is transferred from tube to tube three times to isolate sDNA and remove QuARTS reaction inhibitors.
- sDNA capture beads, which incorporate DNA probes to target and isolate the DNA of interest, are added. Samples are placed into a proprietary capture incubator that mixes and runs through a thermal gradient to bind target sDNA to the beads.
- After incubation, the sample is moved to the capture aspirator. Here, the small beads and DNA are magnetically captured from the liquid. Capture wash is added to the tubes as a buffer to maintain the integrity of the DNA.
- In the final automation step, the primary stool sample and the fecal hemoglobin sample are processed in the liquid-handling robotic system and data is read in real time.
- All information related to the processing of the sample is captured in real time using a laboratory information system and any collection issues are caught and reported.
Once analysis is complete, patients receive the test results from their prescribing healthcare provider in about 2 weeks.
Patients may request a copy of their Cologuard results directly from Exact Sciences’ laboratory. Such requests must be made in writing, using forms provided by the laboratory. Under US Department of Health and Human Services regulations, patient results must be provided within 30 days of the availability of the result.
Exact Sciences provides test results first to the ordering provider, and afterward to patients who have requested to receive the results directly. In most instances, patients receive their copy of the test results within one day of their provider receiving them. The company reports that several patients have requested to receive their test results directly, and that the processes for delivering the results seem to be working well.