Your team spends a lot of time and effort collecting biosamples—the basis for your and others’ research for perhaps years to come. You want to make sure that they will be readily accessible, easily managed, properly preserved, and well documented. Obviously just stashing those tubes and plates of DNA, RNA, blood, plasma, serum, urine, tissue, protein, or cell lines into the freezer isn’t the best plan for long-term storage, but what is?
Here we share three expert’s advice about options, from better managing specimens in-house to partnering with or outsourcing to a biobank.
Now and later
The best plan is to plan ahead. It’s a no-brainer to know the protocols and prepare for experiments before you run them—get out the EDTA-coated collection tubes, have a bucket of ice standing by, ready reagents into tubes to receive tissue samples. Know whether the samples are to be used immediately, aliquoted, or preserved for later. And, of course, make sure all containers are appropriate for the application (can your vial handle liquid nitrogen?) and appropriately labeled (more on that later).
The same goes for making sure permissions are all in place: From the institutional review board (IRB), for example, and patient consent forms if they’re applicable. Clinical data should be linked to the physical samples, but “you need to de-identify it. It’s not recommended to have patient information or even protocol information on the sample tube or container,” cautions Elena Bogatenkova, program director at the MD Anderson Cancer Center Institutional Tissue Bank.
Planning ahead also means designing studies and collecting samples “that make them useful and withstand the test of time,” explains Andrew Brooks, COO at RUCDR Infinite Biologics at Rutgers University, and CSO of Brooks Life Sciences. He urges researchers to “think about opportunities today for collecting the sample, but also the opportunities that are going to exist tomorrow.”
For example, the NIH collections that Brooks manages always included cryopreserved peripheral blood mononuclear cells (PBMCs) as an insurance policy “because if we ran out of DNA we could make a cell line and make more.” Little did they know that those hundreds of thousands of lymphocyte samples would become an invaluable source for patient- and disease-specific induced pluripotent stem cell (iPSC) lines a few years later.
Sample collection, processing, and storage amounts to less than 10% of the total cost of recruiting a patient for a clinical trial, he adds. But the opportunity costs are far greater.
Label, document, track
Best practices, standard operating procedures, and checklists for procuring and storing samples are widely available—from the College of American Pathologists (CAP) and the International Society for Biological and Environmental Repositories (ISBER), for example.
“The process is not that difficult,” says Bogatenkova. But it requires training, and clean, reliable, and monitored equipment, and data management.
The best archives will have a documented chain of custody from cradle to grave. Not only about the protocol and patient (or experimental subject, in the case of animal models, for example) and who procured the sample and when, but information about how it was processed, the time it took to go from patient to freezer, which freezer and where in the freezer it was stored, the temperature of the freezer, any deviations, and everything in between.
“Certain specimen types have preferential storage conditions. A lot of blood products are going to be stored at -80, for example, whereas isolated cells and tissues are preferentially stored” below the glass transition temperature, “in LN2 [liquid nitrogen] if it’s available” explains Cole Drifka, program director, Biorepository and Laboratory Services at the University of Minnesota’s Clinical and Translational Science Institute.
Many investigators don’t follow best practices, says Brooks. They may identify samples by writing with a Sharpie on the tube, or a piece of lab tape that goes on the tube, and put the sample in a rack, or into a box, in the freezer. The writing can become smudged, the tape can fall off, the box can get moved around or misplaced. Many people also use a written notebook or an Excel spreadsheet to keep track of storage location and associated data. Thankfully, there arenow open-source and commercial software and tools available to optimize tracking and managing samples, including generation of barcoded labels.
Biobanking
Whether you need to archive samples just for your own projects, or to share with the greater scientific community, it may be a good idea to consult with a repository on aspects of sample procurement, management, and storage, including an assessment of infrastructure. Many researchers will elect to purchase the necessary software and equipment and hire and train personnel, but others may opt to work with a biobank to do much of the work for them.
Why outsource? “One reason is space availability. Another is backup and environmental monitoring and all of that—a typical lab might not be on generator backup, LN2 backup, so there’s the security aspect as well,” says Drifka. “Some of our freezers you can think of as rent-a-freezers. We simply ensure the integrity and security of the samples and kind of manage the pulling and adding of the samples on behalf of the investigator.”
Another reason? “At least with our [biorepository] investigators if they store with us they are able to tap into our specimen management software, and some of the benefits that come with that,” he adds. “Namely, ours allow us to link specimens automatically to patient health information in EPIC. And there’s strong collaboration with bioinformatics here.”
No matter how modest your biosample storage needs, tap into the expertise of those who have come before. Little tidbits (like not to buy a frost-free freezer because it goes through microthaw cycles) and sage advice (like having a disaster recovery plan) can make hard-earned samples valuable long into the future.