Every test tube connects to a patient: Quality control of specimens in the pre-analytic phase  


Each day, some 40 to 45 thousand specimens are shipped to Mayo Clinic Laboratories in Rochester, Minnesota, from hospitals and other health care organizations around the world. And for every sample, there’s a patient to whom it belongs, someone on the other end hoping for answers to a challenging, perhaps even life-threatening, condition. Which is why getting all specimens to Rochester on time and still in optimal testable condition is the main priority for Aline Mossmann, logistics quality specialist, and her team. 

"When we meet with other teams and we’re looking for options with companies transporting our specimens, the number one factor is always transit time because every single specimen is important,” she says. “But when you’re talking about a sick child, or an irretrievable sample that involves a complicated process to collect, I tend to get really emotional about maintaining a level of quality.”  

Thomas Griffin, senior manager, Mayo Clinic Laboratories Operations - Global Logistics, which oversees transportation of all specimens, concurs, “The whole objective is to get the specimen through the door and into Specimen Operations, so they can get it to a lab in time to get a result back to the physician today,” he says.

“We’ve done a lot of research on the impacts of a delay. In some cases, a test result delay might mean the patient has to spend an extra night in a hospital. When they don’t get released, you’re talking about thousands of dollars a day for that. The impact of not getting the work through ripples out across the country, and there are people who really need their results today.”   

Temperature is paramount

Domestic shipments include about 230 courier routes in markets throughout the U.S., from big cities to rural areas and everything in between.

“We have couriers going into hospital and clinic labs, packing up the specimens, preparing a box for shipment, and handing it off to a transportation carrier, a charter flight, or commercial airline carriers,” says Griffin. “We’ve really diversified to mitigate the risk of delays. So we have done a lot more shipping on commercial air carriers, and we have expanded our relationship with our charter flight operator that specializes in time-sensitive medical products.”

Getting specimens delivered in the right condition primarily refers to temperature. Depending on the type — blood, tissue, or urine, for example — each specimen must be kept at one of three temperatures:  

  1. Frozen (on dry ice)
  2. Refrigerant (2 - 8 degrees Celsius)
  3. Ambient (over 10 degrees Celsius)  

Once a sample arrives at Specimen Operations, its temperature is closely monitored through the entire accessioning process until the moment it reaches one of Mayo Clinic’s 65 specialty labs for testing. Temperature regulation starts with the way a specimen is packed. Mayo Clinic Labs uses custom “berry boxes,” which have a distinctive cranberry or raspberry color so carriers can more easily sort and prioritize them for shipping to Rochester. Berry boxes come in 5-, 10-, and 20-pound sizes, and also a “double berry,” which combines two 10-pound styrofoam containers.

“The double berry allows clients to send refrigerant, ambient, or frozen specimens in one box if they would like to,” says Kathryn Pearce, quality management coordinator in Specimen Operations. “A shipment from a client could have one specimen, or it could have a hundred specimens. It all depends on what the client had to ship that day.” 

While being processed, a specimen is stored in a separate Styrofoam container at its required temperature, a state known as “individual styro-stabilization.” The management team in Specimen Operations supports and helps facilitate improvements to specimen processing, according to Pearce. For example, when it was identified that temperature changes of specimens on the floor were resulting in test cancellations, the team immediately addressed the issue.  

“We increased what we call our ‘water spiders,’” explains Pearce. “Every person on water spider duty has a cart, and they get assigned a route and specific temperature category. They go by each lab assistant’s desk to pick up specimens that have been accessioned, and they check each container label for the temperature. If they find a label that is not at the correct temperature—like, maybe a lab assistant put it in the wrong bucket to be picked up—we can assess those quickly, versus waiting till the very end of the processing line. So we’ve been able to save multiple samples this way and reduce our cancellations.”  

The "happy path"

During the COVID-19 pandemic’s peak, specimen volume topped 94,000 in a single day. But no matter the volume, quality is always paramount. “When you think about the volume that comes in, it’s so important that everybody does their steps properly,” says Angie Reese-Davis, senior manager Specimen Operations.  

Accessioning steps include a new label placed over the client label so that each specimen becomes a Mayo Clinic sample. It is then entered into a laboratory information system (LIS). “We also make sure we archive the specimen for the duration that our lab will need access to it,” says Reese-Davis. 

A specimen may then move to Liquid Handling, for example, where staff perform liquid pour-offs and aliquots. “Say you have a sample in one test tube, but the lab needs to perform three tests: our staff in Liquid Handling will do aliquots into multiple tubes. We also get stool samples ready to be tested by the lab.”

The area operates 24/7 over three shifts with a staff that hovers around 300 people. The accessioning team alone accounts for about 100 lab assistants, spread across the floor in groupings of 10 to 12 per pod.  In addition to the accessioning staff, each pod includes a staff lead, a triage lead, and a quality assurance assistant.

The process by which specimens move through accessioning is fondly referred to as the "happy path," according to Reese-Davis.

“When something falls off the happy path, accessioning staff have a process for how they interact with either the lead or the quality staff,” she says. “So that group works cohesively together throughout the day. And all the pods are pretty much connected with leads bringing the work to each one. They manage the carts, they manage the specimen styros going into each pod, so our accessioning staff don’t need to leave their workstations as much — of course, they do get breaks. We’ve designed the happy path to be a well-oiled machine with the right people in the right place within that pod.”

Though Specimens Operations is considered the pre-analytic stage, specimens are managed with the same standards as if it were an actual lab. Reese-Davis brings her background in hematopathology and anatomic pathology labs to the mix. “Even though we don’t do testing here, we’re still doing pre-analytics,” she says. “We have the College of American Pathologists come in and do our accreditations, and we have safety audits. So we’re really held to the same standards as any laboratory.”   

Dangerous goods

Every morning, there’s a team huddle within the pods, which further reinforces quality and ways to improve it. “We have quality indicators of red and green that we discuss,” says Reese-Davis. “And Kate’s team has been doing Focus Fridays, where they pick a topic, like infectious handling, to educate staff. Kate has made these sessions a positive experience, and we tailor these educational topics to things we’ve noticed on the floor.”    

Speaking of infectious handling, most of the specimen shipments are considered “dangerous goods”—such as COVID-19, collected with a swab then put in a viral media for transport. “A COVID sample is basically fixed in a media so it’s not an imminent danger to you,” says Griffin. “But if, instead of a swab in a tube, you had an actively growing TB culture, that would be a Category A infectious substance because it’s in a state that, if the specimen leaks, the pathogen could be released and we’re all in danger, because TB goes airborne so easily.”    

The handling of dangerous goods requires special training and certifications, not only for staff but also for couriers and carriers, and anyone handling the specimens in transport and the accessioning process.

Taking the domestic model overseas

In the past few years, Mayo Clinic Labs has replicated its domestic courier-based shipping model offshore to support international expansion, which currently includes 60 countries. In countries where regulations allow, couriers pick up samples from hospitals and clinics to be consolidated and sent to Mayo Clinic Laboratories.

“Our international logistics team is relatively new,” says Griffin. “By creating an additional support team for international markets, we can now give equal focus on both domestic and international activities, which has really helped us grow.”  

Some of the rarer specimens come from international clients in places like Hong Kong, Singapore, Bogota, Saudi Arabia, Sao Paulo, Dubai, and Abu Dhabi.

“It’s a lot more selective, what some international clients can send us,” says Griffin. “You don’t get a lot of the more common test requests that we get in the U.S. There’s often more genetics and pathology involved. If you’re willing to send a specimen halfway around the world to Rochester for genetic testing, there’s something very serious going on and you want to find out what it is.”  

Whether a specimen comes from a domestic or international client, the team always treats it as the most precious of cargos. Mossmann sums it up this way: “Even though we’re processing all those specimen boxes, we keep close in mind that there’s a patient on the other end of every test tube we receive. So the needs of the patient will always come first.”           

Additional Communique articles

Chris Bahnsen

Chris J. Bahnsen covers emerging research and discovery for Mayo Clinic Laboratories. His writing has also appeared in The New York Times, Los Angeles Times, and Smithsonian Air & Space. He divides his time between Southern California and Northwest Ohio.