Histology Laboratory

The histology laboratory at IGB, processes, trims and stains specimens that require non-standard processing for light microscopy. For routine and standard histological service, we recommend contacting the Vet Med Histology Lab (217-333-0383 or ibagchi@illinois.edu). NB: Samples may be dropped off Monday – Thursday between 2:00 to 4:00pm. This laboratory caters to research, and charges by the hour.  Most cases are presented as formalin fixed tissues, and embedded in paraffin for histologic slide preparation. A wide variety of special and immunohistochemical stains are available by request. To submit a sample, please contact Kingsley Boateng at kboateng@illinois.edu. You may also download and complete a sample drop-off form from here.

Fixation of Tissues:

Nearly all tissues can begin with fixation in 10% Neutral Buffered Formalin.  Fixation alters tissue by stabilizing protein from further change.  A fixative changes soluble cell components into soluble substances so that those substances are not lost during subsequent processing steps.  Fixative volumes should be at least 10 times specimen volume.  After 12-24 hours, specimens can be transferred to just enough formalin to keep moist, or placed in 70% Ethanol indefinitely.  If samples are to be mailed out, be advised that formalin freezes at low temperatures, damaging the tissue.  To prevent freezing add 1ml of ethanol to each 9mls of 10% formalin.

Tissue submission for Paraffin Embedding:

For the best preservation of tissue morphology, it is recommended that tissue thickness be between 0.3 and 0.5mm (the thickness of a nickel).  Paraffin embedding is used to provide a medium to cut sections as thin as 3 microns (a micron=1/1000 of a mm).  Paraffin embedded tissues are well preserved, with good morphology being present in archival blocks decades after the tissue has been embedded.  This technique allows for a wide variety of staining techniques including routine and special histochemical staining, immunohistochemistry, in-situ hybridization and PCR.

Tissues for Frozen Section Histology:

For best results, tissue for frozen section histology should not be fixed in a chemical fixative.  Tissue to be frozen should be placed in a mold and surrounded by a cryoprotectant (e.g., OCT) before being snap frozen.  Tissue should be frozen as soon after harvesting as possible to prevent autolysis from occurring.  Adequate morphology can be obtained with frozen sections though not as good as with paraffin sections. Most routine histologic stains can be performed on frozen tissue as well as immunohistochemistry, immunofluorescence and enzyme histochemistry.

Tissue Staining:

Hematoxylin & Eosin (H&E) is the most commonly performed histologic stain.  H&E staining is used for general morphology and reference.  Hematoxylin is used for nuclear chromatin delineation.  Eosin is used as a secondary stain for non-nuclear components like cytoplasm, muscle, and connective tissue.

Other Staining:

Immunohistochemical staining is available.  For new antibodies or unknown protocols please see the Histology staff for an antibody work-up.  The turn-around times for this varies depending upon the antibody.  For routine antibody staining faster turn-around times will be possible.