Cryo-Gel™ is a highly viscous embedding medium for frozen sections that will "stay put" and not "run" when dispensed onto a block holder (e.g. the specimen stage). The gel is packaged in a unique pump dispenser bottle that can dispense Cryo-Gel in literally any position. One full pump stroke will dispense approximately 2.5 ml. For most specimens, between 1/4 and 1/2 stroke is generally sufficient. The diameter of the dispensed gel on the block holder should be the size of a pea (approximately 1 cm diameter) depending on the size of the specimen being mounted.
Cryo-Gel is biodegradable and completely water soluble. The freezing point of the gel is that of water, namely 0° C. It is not necessary to spread the gel on the block holder.
After dispensing the gel, the bottle is held in place and the pump is released. The dispenser has a built-in "guillotine" that will cleanly sever the gel from the pump spout, preventing any "stringy" medium residue from pulling away from the gel when the bottle is removed. For optimum results easy to follow instructions are printed on the bottle label.
Easy to follow procedures for Cryo-Gel™
A "safety layer" of gel should be made before embedding the tissue specimen. Dispense gel onto a room temperature block holder. In a few seconds the gel will flow into the grooves and other features of the surface. Use a cold heat extractor to flatten and freeze the gel. This layer of gel will then be securely anchored to the block holder. The blocks can be prepared in advance and stored up to 8 hours inside the cryostat. The gel is water based and longer storage may cause the gel to shrink.
When ready to embed the tissue, dispense additional gel on top of the safety layer. Place the tissue specimen on top of the gel. Do not submerge the specimen below the surface of the gel since this will result in unnecessary trimming. Lower the cold heat extractor directly on top of the specimen. The somewhat flattened specimen will be uppermost in the frozen gel. You may find that the heat extractor adheres slightly to the frozen surface, but it can be easily "broken loose".