I. Sample Preservation

1. Appropriate Preservation Solution
   • The collected saliva sample should be placed in the special preservation solution provided in the kit. The composition of the preservation solution is usually carefully formulated to maintain the activity of cells in the sample, prevent the growth of microorganisms, and inhibit the degradation of nucleic acids. For example, some preservation solutions contain buffers that can stabilize the pH of the sample, preventing enzymes in the saliva from damaging components such as nucleic acids.
   • Ensure that the swab is completely immersed in the preservation solution, allowing the saliva adsorbed on the swab head to fully contact the preservation solution. This ensures that all components in the sample are uniformly protected by the preservation solution. If the swab is not fully immersed, part of the sample may deteriorate due to exposure to air or insufficient contact with the preservation solution.
2. Preservation Temperature
   • Generally, saliva samples should be stored in a low – temperature environment. The ideal storage temperature is usually around 2 – 8 °C. This temperature range helps slow down cell metabolism, inhibit the growth of microorganisms, and reduce the activity of nucleases. The sample can be placed in the refrigerator’s cold storage compartment, but avoid contact between the sample and other items in the refrigerator to prevent cross – contamination.
   • For some special testing projects, such as those requiring long – term sample storage or detecting components extremely sensitive to temperature, a lower temperature may be required, such as – 20 °C or – 80 °C. In such cases, specialized low – temperature storage equipment, such as ultra – low – temperature freezers or liquid nitrogen tanks, should be used.
3. Sealed Preservation
   • The container for storing the sample must be well – sealed. This prevents the evaporation of the preservation solution, protects the sample from external contamination, and avoids sample leakage. Use the sealing cap provided in the kit to ensure that the cap is tightened, and regularly check whether the cap is loose during storage and transportation. If the preservation solution evaporates, the concentration of the sample may change, affecting the test results; if the sample leaks, it will not only result in sample loss but may also pose a hazard to the surrounding environment and personnel.

II. Sample Transportation

1. Select the Appropriate Transportation Container
   • Select the transportation container according to the sample’s storage temperature requirements. For samples stored at 2 – 8 °C, an insulated box with ice packs can be used. The number of ice packs should be adjusted according to the transportation time and environmental temperature to ensure that the sample remains within the appropriate temperature range during transportation.
   • For samples that need to be transported at lower temperatures, such as – 20 °C or – 80 °C, a special dry – ice transportation box is required. Dry ice can provide a lower temperature to ensure the quality of the sample. When using a dry – ice transportation box, pay attention to the amount of dry ice and its placement to avoid the dry ice directly contacting the sample and causing it to crack.
2. Prevent Vibration and Collision
   • During transportation, try to avoid subjecting the sample to vibration and collision. Cushioning materials such as foam plastics and sponges can be filled around the sample container. These cushioning materials can absorb the energy generated by vibration and collision, protecting the sample from damage. Especially for saliva samples containing cells or nucleic acids, severe vibration may cause cell rupture or nucleic acid chain breakage, affecting the test results.
3. Comply with Relevant Regulations and Labeling
   • If the saliva sample is transported for medical diagnosis or scientific research purposes, relevant laws and regulations need to be followed. For example, special permits and labeling may be required when transporting samples containing pathogens. The transportation container should be labeled with the nature of the sample (such as whether it contains pathogens, the degree of danger, etc.), storage temperature requirements, contact person, and contact information, so that problems can be dealt with promptly if they occur during transportation.