Some specimens or coolers will be labeled “FROZEN” and must be kept frozen immediately following collection, during transport, and placed into a freezer upon arrival in the testing laboratory. Laboratory freezers are kept at a temperature of 0°C to -23°C.
Examples of frozen specimens can include:
- Fecal specimens for viral testing
- Fertility specimens
- Pleural pneumonia specimens
- Tissue specimens
- Viral specimens
Specimens that need to be kept frozen during the transportation process can be:
- heavy cardboard cartons with tight-fitting lids
- insulated coolers with tight-fitting lids
- dry ice or freezer blocks in the container with a layer of insulating material separating the ice pack and the specimens, such as several layers of paper towels or absorbent materials
- specimens must not come into direct contact with dry ice or frozen blocks to avoid “spot freezing"
CAUTION: Handle dry ice with heavy gloves. It's important to note that if using dry ice to maintain frozen specimens, container lids should not be tight-fitting. This will be discussed later in the course.
