How do you color mice? - briefly
Apply a non‑toxic dye or pigment to the fur or skin after anesthetizing the animal, or use genetically engineered strains that express specific coat colors. Both methods require strict adherence to animal‑care regulations and proper washing to prevent contamination.
How do you color mice? - in detail
Coloring laboratory rodents involves several well‑established techniques, each suited to specific experimental goals. The choice of method depends on the duration of labeling, tissue penetration required, and whether the coloration must be permanent or reversible.
External application of dyes provides rapid, reversible marking of fur or skin. Commonly used agents include non‑toxic acrylic paints, food‑grade dyes, and veterinary‑approved fur dyes. The procedure typically involves:
- Cleaning the target area with sterile saline.
- Applying a thin layer of dye using a sterile brush or swab.
- Allowing the coating to dry for 1–2 minutes before returning the animal to its cage.
Genetic labeling creates intrinsic fluorescence by introducing reporter genes such as GFP, RFP, or mCherry. Standard protocols consist of:
- Designing a construct with a tissue‑specific promoter.
- Delivering the construct via viral vectors (AAV, lentivirus) or CRISPR‑mediated knock‑in.
- Verifying expression through fluorescence microscopy or flow cytometry.
Microinjection of fluorescent dyes or quantum dots into the bloodstream or specific organs yields localized, high‑contrast labeling. Key steps include:
- Anesthetizing the mouse with isoflurane or injectable agents.
- Injecting the dye using a calibrated microsyringe (10–50 µL, concentration 0.1–1 mg/mL).
- Monitoring distribution for 10–30 minutes before imaging.
Hair dyeing, employed for visual identification of individual animals, uses permanent or semi‑permanent pigments. The protocol requires:
- Shaving a small patch of fur.
- Applying a pre‑mixed dye solution according to the manufacturer’s instructions.
- Rinsing after the recommended exposure time (typically 5–10 minutes) to remove excess pigment.
Safety and ethical considerations are integral to all procedures. Use only dyes validated for rodent use, maintain sterile conditions to prevent infection, and observe institutional animal care guidelines. Record dosage, timing, and any adverse reactions in the animal’s log to ensure reproducibility and compliance.