Day 15

November 9, 2011

Today we made more cells. We pipetted 20 microliters of PBS into 4 rows with 6 slots in each row. Then we added 20 microliters of BSA which is a standard protein to the PBS. With the mixture of PBS and BSA, we diluted it several times so there was very little of each chemical by the end slot. We added Cu+2 which changed the clear protein molecules to a light green color. When the Cu+2 was added to the protein, it became Cu+1. Then we added BCA. Two BCAs bind with one Cu+1 which turns the mixture purple. We used this machine to determine how much light is absorbed in each slot. However, according to JM, the numbers seemed to be lower than he expected. He assumed that it was because the cells were frozen for a long time beforehand. Afterwards, JM showed us the way to sterylize pipette tips. This technique is called autoclaving. He placed the tips in a very large machine that pretty much cooks the pipette tips until all of the germs are killed. The machine gets VERY hot. He needed to use gloves when putting in the tips and taking them out. He also wouldn't allow us to stand in front of the machine just in case a big amount of smoke came out. At the end of the day, he explained to us the process of freezing down cells for long term storage. When thawing the cells, he has to go through several steps to slowly cool them down so the cells don't die from a sudden change in temperature. My favorite part today was watching the cells color change of the and learning why they did change. However, it was tough to understand the whole process with all of the different proteins. I tried asking about the significance of each protein like BCA, BSA, and PBS. He really tried to explain it to us but it was very difficult for him to decribe each of them. That it why it was a little hard for me to write this blog because I don't exactly understand what each protein is.