Some specimens must be refrigerated following collection to avoid changes affecting the test results. Laboratory refrigerators are kept at 4°C, with an acceptable range of 2–8°C. So, refrigerated specimens must be maintained between 2–8ºC during transportation.
The courier is responsible for assuring the coolers maintain the specified temperature noted on the cooler. Insulated coolers must have a tight-fitting lid and maintain refrigerator temperature.
Methods for transporting specimens needing to be refrigerated include:
- Plastic cooling blocks that hold blood collection tubes.
- Plastic cups with a slurry of wet ice and water. Tubes or cups must never be inserted into a cup of ice, as this may result in supercooling and freezing at the tube or cup surface, invalidating the test results.
- Frozen gel packs with an insulating layer separating the ice pack and the specimen, such as several layers of paper towels or absorbent materials.
- Insulated coolers that must have a tight-fitting lid and maintain refrigerator temperature.
2. “Fahrenheit and Celsius Temperature Range .” Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Vergleich_Fahrenheit_und_Celsius.svg.
