How many days can a tick be kept for analysis? - briefly
Ticks are suitable for laboratory examination for up to 30 days when stored refrigerated at 4 °C; if frozen at –20 °C, they can remain viable for up to six months.
How many days can a tick be kept for analysis? - in detail
Ticks intended for laboratory examination must be preserved under conditions that prevent degradation of morphological features and nucleic acids. The allowable storage interval depends on the preservation technique, temperature, and the intended analysis (morphology, DNA, RNA).
Preservation methods and typical maximum retention periods:
- 70–95 % ethanol – stable for morphological identification for up to 12 months; DNA quality remains high for at least 6 months, longer periods may reduce yield.
- Freezing at –20 °C – DNA integrity maintained for several months; recommended to process within 6 months to avoid fragmentation; RNA degrades more rapidly, best used within 1–2 months.
- RNAlater or similar RNA‑stabilizing solutions – keep samples at 4 °C for up to 30 days, then transfer to –20 °C for long‑term storage; RNA remains intact for several months under frozen conditions.
- Desiccation (silica gel or airtight containers) – suitable for DNA work for up to 6 months; morphological structures may become brittle after prolonged drying.
Additional factors influencing storage duration:
- Life stage – larvae and nymphs are more susceptible to desiccation; prompt preservation is advisable.
- Species – some hard‑tick species retain morphology longer than soft‑tick species when stored dry.
- Temperature fluctuations – repeated thaw‑freeze cycles accelerate nucleic acid degradation; maintain consistent conditions.
Practical recommendations:
- Process ticks for morphological keys within 2 weeks of collection whenever possible.
- Extract DNA within 1–3 months for optimal yield; longer storage may require additional purification steps.
- Preserve RNA‑focused samples using RNAlater and freeze promptly; aim to complete extraction within 2 months.
- Record preservation details (date, method, temperature) to assess potential impact on results.
Adhering to these guidelines maximizes the reliability of both visual and molecular analyses while allowing flexibility in field collection schedules.