Skin Sectioning Protocol

The skin is the largest organ of the human body and covers the whole body. The skin tissue structure is relatively complex, which poses certain difficulties for section making. The skin structure is mainly divided into three layers, epidermis, dermis and subcutaneous tissue, which contain rich nerve endings and skin appendages, such as sebaceous glands and sweat glands. Different parts of the skin have different structural compositions and characteristics, for example, the epidermis mainly contains keratin, while the dermis and subcutaneous tissues mainly contain collagen fibers and elastic fibers.

Skin Sectioning

The above different components make the hardness and toughness of each layer of the skin different, which often results in wrinkling and easy desquamation in the section, and because the fibrous component of the skin tissue is particularly rich and dense, it adds considerable difficulty to the production.

Extract the specific skin tissue out you want to use your research.
Select a section of the skin that you would like to take cut for slices.
Glue the tissue sample onto the specimen syringe.
Draw the syringe downward to bring the skin tissue core sample into the syringe.
Fill the syringe with 2% agarose (low gelling point, incubated at 37°C).
Cool the entire contents of the specimen syringe with the chilling block. The skin tissue is now embedded in agarose. The agarose will solidify enough for stable sectioning.
Load the specimen syringe onto the slicer.

The flotation bath should be clean and water maintained 5-10º C below the melting point of paraffin. Higher temperatures may separate the tissue and dissolve the ribbons before they are placed on the slides. Lower temperatures will not allow the tissue to relax enough to remove the wrinkles.
Microtome should be on a solid/stable working surface and free of vibration. All clamps should be tightened before beginning. A slow and steady rotation of the hand wheel also reduces vibration and artifacts in sections, such as undulations and venetian blinds. The top image shows this artifact.
Tissue blocks should be coarse-faced (or surfaced) and chilled on ice prior to microtomy. Adding a small amount of water to the ice helps dry tissue soften, improving sectioning and reducing chatter. Nails can be softened in a weak ammonia solution or fabric softener prior to sectioning.
Skin orientation should be inspected after facing the block to ensure that all of the skin samples are embedded correctly and that all of the tissue is exposed on the block surface. Melt down blocks and re-embed when necessary.

For research use only. Not for any other purpose.