Specimen Submission
If you are new to performing necropsies on laboratory animals, then below are a few suggestions that you may find helpful. Please contact us if you have specific questions or are not sure how to proceed. We can provide on-site demonstration and training tailored to the specific needs of your project.
Here are a few helpful hints:
- Be detailed and systematic. You only get one chance to perform a necropsy and the only way to really make a mistake is not to document and collect everything! Even if you don't think that you want to do histology on all organs, collect them all because it's better to have them in fixative "just in case" than for them to be disposed of for good. Have a plan, follow it and be consistent across all of the animals in a given experiment.
- Take photos. As the saying goes, "a picture is worth a thousand words". It is important to know what organs look like grossly when examining them histologically and interpreting histologic changes. Provide descriptions of anything that looks odd or abnormal when you submit your specimens, but also attach photos!
- When collecting a lesion, be sure to collect surrounding normal tissue also so that the interface between normal and abnormal can be visualized microscopically.
- Be gentle with tissues collected for histology. Try not to cause damage that could result in histologic artifacts.
- Perform the necropsy as soon as possible after death. Organs start to autolyze and degrade within hours of death and this process affects their appearance histologically, masking subtle, and possibly important, changes. The intestinal tract and pancreas autolyze particularly rapidly. Putting the body in the fridge slows down autolysis. Do not freeze the body as this will cause histologic freeze/thaw artifacts. An entire mouse can also be put directly into formalin for fixation if you don't have time to do a complete necropsy, provided that you open the abdominal cavity, thorax and cranial vault to allow fixative to enter these spaces and immerse it in a sufficient volume of fixative.
- Use a ratio of AT LEAST 10 parts fixative (most commonly 10% neutral buffered formalin) to one part tissue to be fixed (by volume). If tissues are not fixed properly, we will not be able to provide meaningful interpretation of the histology, and you will lose potentially valuable experimental data.