Where to store a tick? - briefly
Store the tick in a sealed, tamper‑proof container kept at a stable –20 °C freezer, ensuring the environment remains dry and free from contaminants. Label the container with collection date, location, and specimen identifier for traceability.
Where to store a tick? - in detail
Preserving a tick for scientific or diagnostic purposes requires conditions that maintain morphological integrity and, when necessary, nucleic‑acid stability. Selection of a storage method depends on the intended downstream analysis.
A 70 % ethanol solution, stored at 4 °C, retains external features suitable for taxonomic identification. Ethanol penetrates cuticle quickly, preventing decay. For long‑term archives, replace ethanol periodically to avoid dilution from tissue fluids.
Freezing at –20 °C or –80 °C conserves both morphology and DNA. Use sealed cryovials to prevent desiccation. Rapid freezing minimizes ice crystal formation, which can damage cellular structures.
RNAlater™ provides immediate stabilization of RNA and DNA at ambient temperature for up to 30 days, after which samples may be transferred to –20 °C for extended storage. The solution must fully cover the specimen; partial immersion leads to degradation.
Dry storage on silica gel packets, placed in airtight containers, is appropriate for short‑term morphological work when liquid preservatives are unavailable. Monitor humidity; excess moisture compromises specimen integrity.
For each method, adhere to the following procedural standards:
- Assign a unique identifier to the vial or container; record collection date, locality, and host information in a laboratory information management system.
- Use polypropylene or polyethylene tubes resistant to chemical interaction with preservatives.
- Seal containers tightly to prevent leakage and aerosol formation; store in a secondary containment box to meet biosafety regulations.
- Document temperature logs for frozen samples and solution changes for ethanol‑preserved specimens.
When DNA extraction is planned, ethanol‑preserved ticks should be rinsed with phosphate‑buffered saline before lysis to remove residual alcohol. Frozen specimens may be processed directly after thawing on ice to reduce nuclease activity.
In cases where both morphological examination and molecular analysis are required, a two‑step approach is advisable: initial fixation in ethanol for identification, followed by transfer of a sub‑sample to RNAlater™ or freezing for nucleic‑acid preservation. This strategy maximizes data yield while minimizing specimen loss.