Struggling with Animal Injections? A Guide to Solve All Your Problems!
In disease treatment research, drugs need to be delivered into the body via oral administration, injection, or other routes to exert their therapeutic effects. In basic scientific research, using tool viruses such as lentiviruses and adeno-associated viruses (AAV) through injection into animal models is a critical approach for studying gene function, metabolic pathways, and disease mechanisms. Selecting an appropriate in vivo injection strategy is essential for the reliability and reproducibility of experimental results. Below, we systematically introduce the operational procedures and precautions for common injection routes to provide guidance for researchers.
1. How to Achieve Efficient Systemic Delivery via Tail Vein Injection?
Tail vein injection is widely used in mice and rats for systemic administration, suitable for the efficient delivery of viral vectors, drugs, or cells.
Procedure:
1. Gently pick up the mouse and place it on the cage lid or the back of the operator’s hand for calming.
2. Secure the animal in a restraint device, expose the tail, and wipe it with an alcohol cotton ball or apply mild heat (e.g., warm water or lamp照射) to dilate the blood vessels.
3. Straighten the tail and identify the position of the tail vein.
4. Insert the needle at the distal one-third of the tail. Minimal resistance and smooth insertion indicate proper placement within the vessel.
5. Slightly pull back the syringe plunger; if blood reflux is observed, proceed with slow injection.
6. After injection, apply gentle pressure with a cotton ball for about 1 minute to prevent bleeding.
7. Return the animal to its cage for observation.
Additional Notes:
The viral injection volume must be strictly adjusted based on body weight and experimental requirements. For example, a 6-week-old rat (approximately 150 g) can be injected with AAV9 at a typical dose of 3×10¹³ – 1×10¹⁴ v.g./kg, with a volume not exceeding 200 µl.
2. Is Temporal Vein Injection Suitable for Neonatal Mice?
Temporal vein or facial vein injection is commonly used in neonatal mice due to their relatively prominent vessels and good visibility during operation.
Procedure:
1. Place the pup on wet ice for 30–60 seconds for mild anesthesia, avoiding prolonged exposure to prevent complications.
2. Prepare a syringe and draw up approximately 30 µl of the reagent (e.g., Evans blue).
3. Secure the pup’s head under a microscope and identify the temporal vein.
4. Insert the needle with the bevel facing upward; blood reflux indicates successful entry into the vessel.
5. Inject slowly and observe whether the vessel undergoes blanching.
6. Leave the needle in place for 10–15 seconds after injection to prevent reflux.
3. What Are the Key Operational Details for Intraperitoneal Injection?
Intraperitoneal injection (IP) is simple and widely applicable, suitable for administering large volumes of liquid drugs. However, care must be taken to avoid damaging internal organs.
Procedure:
1. Restrain the animal with its abdomen facing upward and head slightly lowered.
2. Select an injection site in the lower abdomen, approximately 0.5 cm away from the midline.
3. Insert the needle at a 30° angle, ensuring the depth does not exceed 1 cm.
4. After confirming no blood or body fluid reflux, inject slowly.
5. Rotate the needle slightly upon withdrawal to prevent leakage.
6. Return the animal to its cage and monitor its condition continuously.
4. How to Perform Precise Subretinal Injection?
This technique is used in ophthalmic disease models and gene therapy research, requiring high operational precision and often assisted by microsurgical equipment.
Procedure:
1. Anesthetize the animal and dilate the pupils.
2. Prepare a microsyringe with a viral solution volume of 1.5–2 µl.
3. Open the eyelid and place a coverslip to visualize the retina clearly.
4. Create a perforation posterior to the corneal limbus and insert a 33 G blunt needle.
5. Inject the viral solution slowly and observe the formation of a subretinal bleb.
6. Withdraw the needle gently and close the eyelid.
5. How to Achieve Nucleus-Specific Delivery via Stereotactic Brain Injection?
This method is used for precise injections into specific brain regions, relying on a stereotaxic apparatus and brain atlas coordinates.
Procedure:
1. Anesthetize the animal and secure its head in the stereotaxic frame.
2. Shave and disinfect the scalp, then make an incision to expose the skull and identify the bregma and lambda.
3. Determine the coordinates of the target nucleus based on the brain atlas and drill a burr hole.
4. Use a microinjection system to slowly inject the virus.
5. Leave the needle in place for a few minutes after injection to prevent reflux.
6. Suture the skin, resuscitate the animal, and monitor it postoperatively.
6. What Are Other Common Injection Methods?
Additional methods include intramuscular injection (IM), subcutaneous injection (SC), intradermal injection (ID), intragastric administration (IG), intrathecal injection (IT), and spinal nerve injection, each suitable for different research purposes:
· Intramuscular injection: Commonly used for vaccines or gene therapy, often targeting the quadriceps or lateral thigh muscles.
· Subcutaneous injection: Suitable for slow-release formulations; lift the skin to create a "tent" during injection.
· Intradermal injection: Used for immune challenge experiments; a visible bleb should form upon injection.
· Intragastric administration: For oral drug delivery; use a ball-tipped gavage needle to avoid entering the airway.
· Intrathecal injection: Suitable for central nervous system drug delivery; requires accurate identification of the intervertebral space.
· Spinal nerve injection: Used in peripheral nerve disease models; involves high operational complexity and often requires microdissection techniques.
Conclusion
Selecting an appropriate in vivo injection method requires comprehensive consideration of the research objectives, animal model, reagent characteristics, and operational feasibility. Strict adherence to operational standards, emphasis on animal welfare, and ethical requirements are fundamental to ensuring scientific validity and reliability of experimental results. It is recommended that novice operators seek guidance from experienced personnel and utilize resources such as video tutorials and experimental guidelines to improve operational consistency.
Product Information
|
FGF21 Recombinant Rabbit mAb (S-2567-21) |
Host : Rabbit Conjugation : Unconjugated |
|
|
Hint1 Recombinant Rabbit mAb (S-2693-67) |
Host : Rabbit Conjugation : Unconjugated |
|
|
LPA Rabbit Polyclonal Antibody |
Host : Rabbit Conjugation : Unconjugated |
|
|
p16INK4a Recombinant Rabbit mAb (S-2573-6) |
Host : Rabbit Conjugation : Unconjugated |
|
|
LRRC15 Recombinant Rabbit mAb (S-2473-43) |
Host : Rabbit Conjugation : Unconjugated |
|
|
EEA1 Recombinant Rabbit mAb (S-2604-39) |
Host : Rabbit Conjugation : Unconjugated |
