Scanning Slides

Last Friday (November 22nd), I returned to RPI for more work! Currently, we have three methods of getting the protein that we are focusing on. The first method involves growing the protein in E-coli and lysing the cells. The other two methods involve extracting the protein from human brain cells using different buffers (which I will call buffer R and buffer T). As I have demonstrated in previous posts, our protein consists of two loops that react with each other to form a tight junction.

In all of our previous experiments, we have used only parts of the protein in microarray experiments. Today, we analyzed microarray slides that tested the entirety of the protein for the first time. We used a scanner to analyze slides that tested protein derived from each of the three methods. We scanned nine slides total. 100%, 50%, 10%, and 1% dilution for the E.Coli protein, 50% and 10% dilution for the buffer R protein, and 50% and 10% dilution for the buffer T protein. We scanned each group separately for comparison. With each group, we also scanned a control slide which consisted of no focus protein- only primary antibody- to make sure the antibody was binding specifically to the focus protein. Examples of good and bad binding of the primary antibody are seen below. The blue circles represent focus protein that was bound to the microarray, and the red represents primary antibody. We want the primary antibody to bind only to the focus protein.

For the scan, I laid each slide face down on the scanner, each oriented the same direction. I had to be careful to line them up straight right along the edge of the scanner, so later analysis using spotfinder would be easier to line up the microarray spots. 

An example slide arrangement is seen below for the E.coli slides. 

We scanned the slides first at 200 microns, then at 50 to get the most precise scan possible. After getting the images from the scanner, we imported them into a program called spotfinder to analyze the intensity of each spot. The resulting data wasn't perfect, but it was a good start! 

I will not be able to go to RPI next Friday (November 29th) due to the Thanksgiving holiday, but I look forward to returning on December 6th!