How do you administer medicine to a rat using a syringe? - briefly
Using a sterile 1 ml syringe fitted with a 27‑30 G needle, gently restrain the rat by holding its tail and scruff, then identify the appropriate site such as the dorsal neck fold for a «subcutaneous» injection. Insert the needle at a shallow angle, depress the plunger to deliver the calculated dose, withdraw the needle, and apply brief pressure to prevent leakage.
How do you administer medicine to a rat using a syringe? - in detail
Administering a drug to a laboratory rat with a syringe requires preparation, restraint, injection technique, and post‑procedure monitoring.
First, select an appropriate syringe and needle. A 1 ml syringe with a 27–30 G needle provides sufficient precision while minimizing tissue trauma. Attach the needle securely and verify that the plunger moves smoothly.
Second, prepare the medication. Draw the exact volume required, eliminating air bubbles by tapping the barrel and gently expelling any trapped air. Ensure the solution is at the correct temperature (typically room temperature) to avoid vasoconstriction.
Third, restrain the animal. Use a clean, well‑ventilated restrainer or gently grasp the rat in a thumb‑and‑forefinger grip, exposing the injection site without causing undue stress. The preferred sites are the lateral tail vein, the subcutaneous space over the dorsal thorax, or the intraperitoneal cavity, depending on the drug’s intended absorption.
Fourth, perform the injection:
- Subcutaneous (SC) – Pinch a fold of skin on the dorsal flank, insert the needle at a shallow angle (≈30°), and release the skin gently while delivering the dose.
- Intraperitoneal (IP) – Locate the lower right quadrant of the abdomen, insert the needle at a 45° angle toward the midline, and advance until a slight “pop” indicates entry into the peritoneal cavity; inject slowly.
- Intravenous (IV, tail vein) – Warm the tail to dilate veins, secure the tail with a small tape loop, insert the needle bevel‑up at a 20–30° angle, confirm blood return, then administer the medication steadily.
Throughout injection, maintain a steady plunger movement to avoid rapid pressure changes that could cause hemorrhage or reflux.
Finally, observe the rat for immediate adverse reactions. Return the animal to its cage, monitor for normal behavior, respiration, and mobility for at least 15 minutes. Record the administered dose, site, and any observations in the laboratory log.
Adhering to aseptic technique, proper restraint, and precise needle placement ensures reliable drug delivery while minimizing animal discomfort and experimental variability.