RM+Week+of+June+23

Back to RM's Summer Research


 * June 23, 2008**

I made a new sample on mica with 20 microliters of annealed soltuion, with a deposition time of 2 minutes. Took 3 decent AFM images with areas of 5 micrometers squared, 2 micrometers squared, 1 micrometer squared. On these images, I noticed beads instead of webs/network formations and holes. However, I had a little bit of trouble obtaining images - there was a lot of noise.


 * June 24, 2008**

Made a new sample on mica with 20 microliters of solution, with a deposition time of 5 minutes. Took many AFM images of varying areas. However, I noticed a return of the web-like structures. The beads that were observed were too small to be DNA rafts. Additionally, most of the particles were clumped together. What I noticed when comparing these images to yesterday's images is that those from yesterday had the particles aligned in a specific direction.

Also, after AL viewed his samples under the AFM, I decided that the deposition time should be 2 minutes because his particles were more spread apart, just like mine was yesterday after a deposition time of 2 minutes.

Ex. of web-like structures on mica surface


 * June 25, 2008**

Today was a horrible day. My samples proved fruitless, and every time I tried making a new sample, I dropped it. However, I need to make a new stock solution.


 * June 26, 2008**

I made a new stock solution yesterday with 5 microliters of each DNA strand (for a total of 80 microliters) + 10 microliters of the TAE/Mg 2+ buffer + 10 microliters of dH20. So, the total volume for the solution was 100 microliters. Today, some presented their projects at our group meeting. Afterwards, I prepared a sample from the new stock solution made yesterday. The deposition time was 3 minutes. I did not do 2 minutes because I thought that the new stock solution may allow me soak the mica chip for a little longer. However, I was unable to use the AFM because it was completely booked for the day.


 * June 27, 2008**

Today, I viewed the sample from yesterday under the AFM. However, I kept getting web-like structures. One image seemed to have bead-like objects strung together, which is what I'm supposed to see happen with the DNA rafts. I saw this possible necklace on an area of 500 nm sqaured.

Also, I made a new sample. This time I decided to dilute the solution because the web-like formations were probably due to the high concentration of the stock solution. Thus, a change in deposition time may not have been enough to allow the particles to spread apart. So, for this sample, I depositied microliter solution of 5 microliters of the DNA solution + 5 microliters of TAE/Mg 2+ buffer on the mica surface.

When I viewed this under the AFM, there were no networks! However, there were many elevated dots. I captured some images, but nothing of great consequence.