Today, the lab took part in a “Data Club” where different researchers present their findings to each other. This morning’s speaker worked with a peculiar compound that binds to the inside of receptors in some neurons. These synthetic compounds amplify the abilities of a different compound, Neurotensin, that binds to receptors on the outside of cells, cooperating to inhibit the effects of psycho-stimulants like cocaine and methamphetamine. Their research with lab mice indicates that the presence of the compound in cells with Beta Arrestin, a transducing protein that helps internalize receptors, vastly reduces craving for addictive drugs, thus potentially breaking the cycle of addiction. There is still substantial work left to be done to confirm the effects of the compound; it’s possible that these positive effects only take place in the cells of mice. However, there is quite a bit of potential for this compound being made into an oral drug, and I’m definitely looking forward to the next Data Club meeting.
For most of the morning, Dr. Masoudi and I waited for vacant spots in incubators to house our bacteria cultures, so I ended up working with Dr. Li Yin in the meantime. Dr. Li Yin set up two columns for chromatography, similar to the ones that Dr. Masoudi and I set up last week with the exception of Dr. Li Yin’s use of an antibody as a filtering agent. After thoroughly washing the columns to flush out any “non-specific binders,” I helped Dr. Li Yin pipette equal volumes of protein-rich solution into the columns where, at their bottom, the antibody resin bound to her target receptor and rejected any other unwanted proteins. Theoretically, the protein that we want should have stuck to the antibody resin. This quick wash protocol is followed by elution, where a “FLAG Peptide” is implemented to compete against our target receptor for attractions with the antibody. The receptor is promptly taken out of the system and dropped into a new container. The contents of this container will be later purified with size exclusion chromatography (the results of which I will get to see tomorrow!) I also helped Dr. Li Yin by organizing, pouring, and washing flasks of insect cell solutions. Not so surprisingly, the wash protocol in the lab is incredibly thorough. Each individual flask is rinsed three times, bleached, and “autoclaved” – where glass objects are put under 120C conditions at high pressure. Nothing survives. Some of my time was also spent spinning our retrieved insect cell solutions in massive centrifuges and separating the lipid-based cell membranes from the unneeded soluble fractions. Although tedious work, it was satisfying to peel the lipid layers from the bottom of each flask, transporting them to smaller containers that were also spun at high speeds and eventually placed in liquid nitrogen. The super cool liquid (in both senses) evaporates around -190C, constituting a temperature so low that water sometimes doesn’t have time to crystallize orderly. The result is a “flash-frozen” solution of insect cells that preserves the structures and prevents any biological processes. We also played with the rest of the liquid nitrogen (safely) by pouring it on the flour and watching the water vapor around it condense 🙂
One of the more dramatic parts of yesterday, something I forgot to mention in the last post, involved dead mice. One of the new M.D.s in the lab had euthanized two mice, dissected them, retrieved tissue from their femurs, spun the results, and transferred the remains to cold containers. Thus, nice mice diced in ice. Yikes.
The liquid is ostensibly volatile because nitrogen boils at room temperature. The atmospheric pressure is not great enough to prevent the nitrogen gas molecules from breaking their inter-molecular attractions and leaving the body of liquid. However, the white gas surrounding the container isn’t nitrogen, but rather water. Because the escaping nitrogen is below freezing, the water vapor particles in the air condense and form a surrounding fog.