Okay. So anything that I have on the body that I'm concerned about that I would like to perform histology on, which I will get to in a second. I take that fresh tissue, I mean, it hasn't been altered or anything, it hasn't been washed, it hasn't been manipulated. I take those pieces of tissue and I put them in a cassette. The cassette is simply a plastic chamber that holds the tissue so that it doesn't get lost or moves around and it stays positioned how it's put when I put it in the gray cassette.
From that point I take that gray cassette and I put it in another container and it is filled with a fluid called formalin. Formalin is simply a preservative that gets the tissue in a state of preservation where it can now be prepared for the next step of processing.
So when I took the piece of tissue off to put in a cassette and I put it in formalin for later processing, that's what I did initially.