How do you give an injection to a rat? - briefly
Use a sterile 27–30 G needle, gently restrain the rat (tail‑hold or restraining tube), locate the dorsal flank or subcutaneous area, and inject the calculated volume at a steady rate. Ensure aseptic technique, proper dosage, and monitor the animal for any adverse reaction.
How do you give an injection to a rat? - in detail
Administering a parenteral dose to a laboratory rat requires preparation, restraint, precise technique, and post‑procedure observation.
First, gather sterile supplies: appropriate syringe (1 mL or 0.5 mL), 27–30 G needle, the drug solution, alcohol swabs, disposable gloves, and a sharps container. Verify the dosage by converting the required milligrams per kilogram to the volume needed for the animal’s weight, and draw the exact amount into the syringe, eliminating air bubbles.
Second, restrain the animal safely. Use a padded restrainer or a gentle hand‑hold technique: place the rat on a flat surface, grasp the scruff of the neck with thumb and forefinger while supporting the hindquarters with the other hand. Ensure the rat is immobilized without excessive pressure that could cause injury.
Third, select the injection route:
- Intraperitoneal (IP): Insert the needle at a shallow angle (20–30°) into the lower right quadrant of the abdomen, avoiding the bladder and intestines. Advance the needle 3–4 mm, aspirate to confirm no blood, then inject the solution slowly.
- Subcutaneous (SC): Lift a fold of loose skin on the dorsal neck or flank, insert the needle bevel up at a 45° angle into the subcutis, and deliver the dose. Release the skin fold after injection.
- Intramuscular (IM): Locate the hindlimb’s quadriceps muscle, insert the needle perpendicularly to a depth of 4–5 mm, and administer the volume. Use the smallest effective volume to reduce tissue distension.
- Intravenous (IV, tail vein): Warm the tail with a heat lamp or warm water for 30 seconds to dilate vessels. Apply a tourniquet or gentle pressure to the proximal tail, insert the needle bevel up at a shallow angle, confirm blood return, then inject the solution rapidly.
Fourth, dispose of the needle immediately in a puncture‑proof container. Release the rat back into its cage, observe for at least 10 minutes for signs of distress, bleeding, or abnormal behavior. Record the procedure details: drug, dose, route, needle size, and any complications.
Adhering to aseptic technique, accurate dosing, and careful handling minimizes animal stress and ensures reliable experimental outcomes.