Q: What is the turnaround time on getting slides back?
A: Many routine histology requests will be complete within a week depending on the number of submissions that we are currently working on. Decalcification, ordering special stains, fixation times, and processing schedules can all increase turnaround times on submission requests. You may contact the Animal Histology Core at any time for a status update on your submission. Accessions are processed in the order received.
Q: What fixative should I use?
A: Of course, this will vary by project, but the majority of tissues can be fixed in 10% neutral buffered formalin (NBF). Paraformaldehyde is not needed for most routine histology and is an added cost and effort to make up. When using 10% NBF, aim for a fixative to tissue volume of 20:1. For eye histology, you may wish to consider Davidson's fixative. Mouse embryos are often best fixed with Bouin's solution.
Q: How long should I fix my specimen?
A: Tissue in 10% neutral buffered formalin (NBF) or paraformaldehyde should be fixed for 24 to 48 hours. Tissue can remain in NBF indefinitely. Glutaraldehyde should not be used in fixation for long periods of time. 2-4 hours of fixation is routine for glutarladehyde. Tissues in Bouin's fixative should be transferred to 70% alcohol after <24 hours of fixation.
Q: My slides don't look quite like I expected. Why?
A: The final slide product is a combination of many factors, including collection, fixation, trimming, processing, embedding, sectioning, staining, and coverslipping. Variables introduced into any of these steps from start to finish, in your hands or in ours, can result in slides that look different than others, have artifacts, or have a poor final result. The AHC strives to provide quality slides at all times. When we encounter tissues that aren't sectioning well, the histologists use their years of experience to assess possible reasons for this and to try to work around the issue. Histology textbooks provide descriptions and examples of common quality issues, and it is usually not difficult to pinpoint the cause. Two of the most common issues we see in our laboratory are inadequate fixation and frozen tissue artifacts. If you have a slide or slides that did not turn out as you expected, please bring them to the attention of the histologist or to Lauren Richey as soon as possible. The pathologist routinely performs quality assessment of a subset of routine and special slides produced as well as all immunohistochemistry slides. If the error is on our part, we will try our best to correct it for you at no additional charge. If the trouble seems to be in collection, inadequate fixation, or other step prior to submission to our lab, we will prepare an example slide of tissue that we collect and give you a collection protocol for optimal slide production in the future.
Q: May I use the microtome, processor or other lab equipment in the AHC?
A: Only the cryostat may be used by investigators. All other equipment may only be operated by AHC personnel. If special processing cycles or procedures are required for your submission, we can accommodate them to the best of our abilities.