Embedding
Tissues are embedded to fit investigators' needs.
The cost of processing and embedding each block is $5.
We require the use of cassettes for specimen delivery rather than tubes or containers. This reduces costly tech time, handling fees, and reduces turnaround time. It also cuts down on errors. Keep in mind that if we cannot decipher tiny handwriting or Greek symbols specimens, we must hold your workorder until the specimen is properly identified so slide labels can be printed. This will delay your results. We suggest you consider using simple accession numbers (such as 09-50A, 09-50B, etc.).
Cassettes, sponges and 10% Formalin are provided at no cost to IHC Core users!
Helpful hint: Do not use a Sharpie to mark your cassettes. The ink from a Sharpie will wash off in alcohol. For best results, use a #3 hard lead pencil to minimize smudging.
Helpful hint: Use at least 15 to 20 times the volume of fixative per volume of tissue. Fixative can be too dilute when large amounts of tissue/cassettes are placed in small volumes of fixative. When in doubt use a larger amount of fixative than you think you may need and change the fixative after 24 hours if needed. We prefer specimens to be delivered in formalin, but 70% alcohol may be used for storing specimens if needed.
Some tissues (i.e. kidney, liver, G.I. tract) benefit from special preparation before being placed in formalin. Click
here for more information on how to prepare your specimens for fixation.
Samples containing dense connective tissue (i.e. bone, cartilage) need to be decalcified before processing. Click
here for more information on decalcification.
Frozen tissues: To prepare frozen samples, submerge tissue in liquid nitrogen immediately after tissue has been harvested. When using liquid nitrogen to freeze samples, quickly submerge samples in liquid nitrogen and then remove. For larger specimens leave in liquid nitrogen for no more than 3 seconds. Wrap the tissue in aluminum foil after it has been removed from the liquid nitrogen and keep on dry ice until the tissue can be stored in a freezer. It is best to deliver samples wrapped in aluminum foil with no OCT. We will place samples in OCT before sectioning. If tissues are fixed before they are frozen please use
sucrose infiltration followed by the liquid nitrogen procedure for better sectioning.
If you have any questions about preparing your samples for paraffin or frozen sectioning please contact the IHC Core for more information before beginning your project.
Faults in fixation can not be remedied at any later stage.
