While collecting samples is step one of any diagnostic procedure, storage is equally important. Without the right approach and lab equipment, scientists risk jeopardising the integrity of a sample and the results generated. So how do laboratories store samples correctly? It all depends on the type of sample collected and the environment in which it’s being stored. Below, we take a look at some of the most common samples collected by laboratories and how they’re stored.
Used to diagnose diseases, evaluate the function of organs and determine biochemical states, blood samples offer incredible insight into human health. Generally, blood samples should be refrigerated immediately after collection and should not remain at room temperature for more than eight hours. If tests cannot be completed within eight hours, blood samples should be stored at temperatures of between +2°C to +8°C. Tests should be carried out with seven days of collection. If this isn’t possible, the option of freezing blood samples at between -15°C to -20°C is an option.
COVID-19 test swabs
COVID tests have played a critical role in helping prevent the spread of the virus. Hundreds of millions of tests have been conducted around the world, including around 400 million in the United States alone. The Centres for Disease Control and Prevention (CDC) decrees healthcare workers should “store respiratory specimens at 2-8°C for up to 72 hours after collection. If a delay in testing or shipping is expected, store specimens at -70°C or below.” This includes mouth and nasal swabs collected for PCR tests.
There are also strict guidelines for packing and transporting SARS-CoV-2, as outlined by documents such as the International Air Transport Association (IATA) Dangerous Goods Regulation and the U.S. Department of Transportation’s (DOT) Transporting Infectious Substances Safely.
Chemicals and other biological materials
From volatile chemicals to human tissue, chemicals and other biological materials require specialised storage procedures. This ensures samples remain stable and don’t degrade over time. Every sample has its own unique properties and it’s essential to understand these to develop effective storage solutions. For example, DNA material stored for long periods should be kept in ultra-low freezers of below -80°C to prevent the deterioration of nucleic acids.