Here you will find common histology questions and our answers. Don’t see your question here? Send us an email and we’ll get back to you as soon as we can!
Q: How Long Should I fix my tissue in NBF or PFA?
A: At least 24 hours for smaller tissues such as lymph node, sciatic nerve, or eyes when using neutral buffered formalin, or paraformaladehyde as both fixatives are quick to penetrate, though slow to fix once they have penetrated. A 1 :20 ratio for these fixatives is also VERY IMPORTANT. 1 part tissue to every 20 parts NBF or PFA. For any tissue such as mouse lung or larger we encourage our users to fix in a formalin derivative for at least 3 days.
Q: How many tissues can I put per cassette?
A: No more than 3. If they are overly crowded or you see a waffle-like pattern impressed on the tissue when the cassette is closed it means your tissue is being crushed and it will not fix or process well. Space must be left within the cassettes around the tissue in order for the reagents to penetrate well.
Q: Does the Core do any special stains?
A: Yes, we sure do! You can find a list of our special stains here. If you do not see the special stain you are looking for, don’t worry. Send us an email and we will discuss ordering the stain or referring you to another core who may have it in house currently.
Q: Does the Core work only with Lineberger Cancer Center members?
A: Nope, we are very happy to work with researchers from any department and others outside UNC!
Q: Does the Core handle only animal tissue?
A: No, though we handle primarily animal tissue, we are also able to work with researchers handling human samples.
Q: Do I need to schedule an appointment to drop off samples or speak to someone in person?
A: No, just drop on by any time between 8:30am and 5pm Monday through Friday.
Q: Does the core do frozen sectioning?
A: Yes we do. We also strongly encourage our users to do a slow freeze when prepping their tissue samples for frozen sectioning. You can find our recommended protocol here.
Q: Should I perfuse my samples?
A: Yes, as possible and appropriate, especially lung, stomach, and brain. These tissues when perfused tissues tend to process much better than if they had simply been placed directly into a fixative.
Q: How do I know which tissues to place in a cassette?
A: Tissues of the same consistency can be placed in the same cassette, such a piece of liver with a piece of spleen. Some tissues such a brain or fat, process best when they are the only tissue in the cassette. Remember the above rule however, never more than 3 tissues in a cassette.
Q: Can you decalcify my specimens?
A: Yes we can, we use Immunocal in our lab and have found it to work very well and to be very gentle on tissues.