Tissue samples in RNAlater for qPCR gene expression

Step 1. Prepare materials

• RNAlater solution; RNase-free scissors and forceps; RNase-free 1.5 or 2 mL tubes.
• Ice bucket (for brief handling only), labels and waterproof marker, gloves (change often).

Step 2. Collect the tissue

• Euthanise the animal according to approved ethical guidelines.
• Dissect the target tissue quickly, ideally within 2–5 minutes, and blot off excess blood with sterile gauze or RNase-free paper.
• Do not leave tissue at room temperature.

Step 3. Cut into small pieces

RNAlater penetrates slowly. Cut pieces no thicker than 5 mm and 20–100 mg per tube. Cut large organs (liver, spleen, kidney, muscle) into several pieces. Do not mince into a paste.

Step 4. Add RNAlater

Use about 10 volumes of RNAlater per volume of tissue. The tissue must be fully covered; do not overfill tubes.

Step 5. Incubate

Keep the tubes at 4 °C for 12–24 hours so RNAlater soaks in fully. Do not freeze straight away.

Step 6. Store and ship

After incubation, store at −80 °C. Ship on ice or cold packs. Avoid repeated thawing and refreezing.

Checklist

• RNase-free tools and tubes; clean gloves, changed often
• Every tube labelled: animal ID, tissue, date
• Pieces small and fully covered by RNAlater
• 12–24 hours at 4 °C, then −80 °C