Although I still have to complete some more training to be able to work with the mice by myself, last week was the first time I was able to observe my postdoc bleeding the mice that are part of his drug trial. His trial involves around 30 mice separated into groups of six. Each group was engrafted with a different hypodiploid ALL patient sample. The sample takes a number of weeks to grow inside the mice, and they are bled every so often to measure the percentage of leukemia cells present in their blood. When their blood contains around 20% of human leukemia cells, half of the mice start to receive treatment, while the other half remains untreated as a control group. There are regulations to ensure that the mice are subjected to the least amount of pain possible, but the only way to justify this treatment is really the fact that this research will contribute to saving human lives.
The mice are bled from their tails, and my post doc tries to make sure he doesn't always cut the same mouse repeatedly when obtaining samples. Only a small amount of blood is required from each animal, which is then analyzed through flow cytometry. To prepare the samples for flow cytometry, the blood samples must first be subjected to red blood cell lysis, as it is the white blood cells that are of interest. The remaining cells are then marked with human and mouse antibodies to determine the prevalence of the human patient sample cells within each mouse. These antibody markers contain a certain pigment that allows the flow cytometry machine to detect levels of antibodies on every single cell.
In addition to the mouse trial, my postdoc is also looking for an expression profile that would determine sensitivity of cancers to the experimental drug, ABT-199. In order to determine possible protein markers, one would need to first determine the levels of expression of various proteins in different cancers. This is what last week's western blot was for, and this week we used phosphoflow cytometry to measure protein expression levels, too. This method involves fixing and permeabilizing the cells and then using antibodies that will mark specific proteins. The flow cytometry machine is then able to measure levels of each antibody, generating a relative expression profile between different types of cells.
Cell culture contamination continues to be an issue in my lab, and my postdoc is ordering some antibiotics that will hopefully solve the problem. I think my pipetting skills have improved quite a bit over these past five weeks. I spent the weekend in LA with my family, which was a welcome break. Hope everyone was able to catch the final.
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