IP injections for NIRF agents on ASK
This information is provided as an example protocol. Always be sure that IACUC or ethic committee approval is in place before beginning any experimental protocol.
Intra-peritoneal (IP) injections are a frequently used method of delivery for therapeutic drugs, cells, and PerkinElmer NIRF agents. When done properly, intra-peritoneal injections are a good alternative to other routes of delivery in mice (IV, SC, ID) in some cases due to the ease of the technique and the limited amount of discomfort afforded to the animals receiving the injections.
Care should be taken to avoid unintentional penetration of the urinary bladder, intestines, or abdominal blood vessels. These events could result in poor anesthesia performance, altered drug/probe pharmacokinetics, and death. In addition, animals that are injected IP can sometimes develop peritonitis, a painful infection of the peritoneal cavity. This can often be avoided, however, if a clean, sterile needle is used, and care is taken to avoid perforation of the bladder/bowel.
- Restraint: When restraining an animal for IP injection, grasp the animal by the scruff of the neck and place the tail in between the thumb and forefinger. Grip firmly but allow for the animal to breathe comfortably. Anesthesia is a not needed for IP injection, but can be used for aggressive animals (e.g. rat) or for injections that may be painful.
- Injection: For IP injections, a 27 gauge or smaller needle should be used. It is important that the injecting needle does not perforate the internal organs of the mouse. With the animal restrained, tilt the animal at a 45 degree angle to allow the intestines to slide forward. Inject in the lower right quadrant making sure that the needle is not too shallow so as to inject subcutaneously, or too deep so as to penetrate the organs or blood vessels of the abdomen. There will be a slight resistance to the needle as it passes through the abdominal muscles. Once the needle is in place, pull back on the syringe slightly to ensure proper placement. A yellowish fluid in the syringe means the bladder has been penetrated, while a greenish-brown fluid means the intestine or cecum have been penetrated. If this occurs, a new needle and injection material will be needed. If no fluid is present when the syringe is pulled back, the injection can proceed. Dispose of the used needle in the approved sharps container.
- Post Injection Care: Following injection, care should be taken to observe the mouse for any unexpected behavior or health status. If the animal exhibits any symptoms that are not expected following the injections, animal facility staff and/or the consulting veterinarian should be notified.