Since treatment of my mice was supposed to last twenty days, Thursday would be the last day of this part of my experiment.
Tuesday and Wednesday went by quickly reviewing some articles and literature, continuing to culture cells, helping out with another experiment at my lab, doing a PCR, and preparing for the twentieth day by collecting and compiling final data and building up several graphs to show the comparative tumor growth progression throughout the twenty days between the treated and untreated groups.
Thursday and Friday would be long days. Starting early in the morning, it was time to begin sacrificing the mice and retrieving all the necessary parts of tissue and organs. After they are put to sleep, the first thing to do is to remove the tumors which have grown considerably on their backs. With each sample, I saved it in three parts. The first piece was placed into formalin for sectioning. The second, likewise for sectioning, I put in an OCT compound on dry ice which protects the tumor tissue while also ensuring that it does not freeze too quickly so as to ruin the tissue. The rest was flash frozen in liquid nitrogen and then put into a -80 C freezer so that it could later be used to make cDNA.
After I collected the tumor of the mouse, it needed to be dissected. Removing the spleen, cells had to be saved for flow-cytometry. For phenotyping, the mononuclear cells were kept while the red blood cells were lysed.
While this seems like a lot, the tumors and spleens were the easy parts. I spent the most time working with the small and large intestines (SI and LI). They had to be saved in the same three ways as the tumors, but before that could happen, they needed to be cleaned out. Removing the SI and LI, I would try to squeeze the poop out with tweezers, before washing them out with tubes till all the fecal matter was gone. This part, quite obviously I presume, would not be the highlight of my week as it was generally tedious and odorous work, if I may say that. Once again, a small piece of each was put in formalin. Another piece, in the OCT compound, however, needed to be sliced horizontally and placed on a membrane in the compound so that when the tissue will be sectioned, I could see the cross section of the entire tissue.
I was hoping to be able to dissect and collect all the samples from the entire twenty mice on Thursday, but I quickly realized that I would be working late into the evening to finish even half. This meant that the other remaining ten I would have to finish Friday, pushing back the date when I could begin running my PCR gels to after the weekend.