User:Brian P. Josey/Notebook/2010/02/15
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Thin walls, and flow cells
Last time I got two suggestion for what I could do to see if I can visualize any movement in the ferritin. The first one came from Anthony. He suggested leaving out a flow cell on the counter top, and putting a magnet next to it, checking after a while to see if there is any change.
The second one came from Koch, and to just use thin-walled tubes for the same tube test that I did Wednesday. For this one, I created 1:10 dilution of the stock ferritin in DI water, and put it into a thin-walled tube. I am going to leave it in the magnetic yoke for an hour again today.
After taking some time to set up the yoke, I decided to add a little more ferritin. The problem was that because of the shape of the tubes, only having 50 uL of ferritin and water would settle to the bottom of the tube, which is angled in a way that I can't put it up against the magnet. The remedy this, I added 7.5 uL of the ferritin, and 67.5 uL of DI water to keep the concentration constant, but allowing the volume to grow.
With a setup that I like, I left the ferritin in the tube out for about an hour, to see if I could get anything to happen. Unfortunately, it didn't really work, and there was no obvious signs of magnetic separation. I noticed a couple of things earlier. When I originally put the extra 7.5 uL of ferritin in the tube, it settled towards the bottom, and there was a clear differentiation between the portion of the sample that had a lot of ferritin, and that which didn't. Placing the small magnet up against the side of tube, the part containing a lot of ferritin was attracted to the magnet, and removing it, the ferritin shot back into solution. However, when I held the magnet up to my earlier 1:10 dilution, and the stock solution, nothing happened.
So I'm having a couple of problems with the set up that I've been using, and a couple of solutions.
I know that ferritin is not as magnetic as the microbeads, so I will try Ant's slide idea, to see if that helps.
I tried the flow cell idea, of leaving ferritin out in a flow cell on the counter for a couple of minutes with a magnet. I created a two chamber flow cell with some of the earlier 1:10 dilutions of ferritin in both chambers. One chamber would serve as a test chamber, to see if there was any effect from the magnet, the other would serve as a control.
After placing the magnet next to one of the flow chambers for ten minutes, there was no difference between it and the control chamber. I then put the magnet directly on top of the ferritin, with the cover glass in between, and again I have no results.
Brian P. Josey 13:27, 16 February 2010 (EST) It's a little frustrating but, I'm working though it. I did see your note on the force form last time, I'm just not a hundred percent sure yet how to calculate it out. I am going to look into it tomorrow, and start working through it. If I can learn how to do it by hand that would be awesome, if I can do it in either MATLAB or Maple, that would be doubly awesome. I had the option to take E&M this semester. It might have helped, but I decided against it, mostly to take the history class. Also, we ordered the conical magnets yesterday afternoon, so they'll come in sometime.