Posted by wettl005 on May 6, 2008 01:22 AM|Permalink
Comments
You mentioned that AFM could be used for in vivo imaging. Since AFM is a topographical technique, I don't understand how this is possible. Could you explain?
I deleted your question, but the reason that AFM could be used in vivo is the allows imaging of the sample without sample destruction. The sample only needs to be held down to a substrate. It seems a bit hard to imagine - I agree, and I don't know how established in vivo imaging is, but sources just mentioned that it could be done. Most AFM studies at this point have been in vitro, however.
According to authors the resolution in the lateral (xy-plane) direction is 1 nm, while the resolution in the vertical (z-plane) is .1 nm. This is while operating in contact mode in either air or a vacuum. I found it surprising the resolution did not improve when performed in a vacuum.
2. (I copied figure 2b into ImageJ and measured the height of the background signal at several points). The background has a standard deviation of about 20 nm, so we could determine a height difference of 60 nm.
According to question 3, the authors use a substrate of polyornithine and laminin, because healthy DRG neurons can attach on this substrate very well. Thus, when you perform the AFM scanning, the cell will not be easy to move or destroy. Besides, they use tapping mode to image the cell. Compared to contact mode, tapping mode doesn't contact to cell surface at all the scanning times, so it cause less damage to cell surface. In the article, they also mentioned that AFM operation in fluids minimizes damage to the cells.
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Comments
You mentioned that AFM could be used for in vivo imaging. Since AFM is a topographical technique, I don't understand how this is possible. Could you explain?
Posted by: Melissa Maurer-Jones | May 6, 2008 10:07 AM
Hey Melissa -
I deleted your question, but the reason that AFM could be used in vivo is the allows imaging of the sample without sample destruction. The sample only needs to be held down to a substrate. It seems a bit hard to imagine - I agree, and I don't know how established in vivo imaging is, but sources just mentioned that it could be done. Most AFM studies at this point have been in vitro, however.
Posted by: Courtney Wettlaufer | May 6, 2008 10:33 AM
1.According to the paper what are teh z and xy resolution for AMF/
2. Based on Figure 1b, what is the limit of detection for measured height differences (c.f. Figure 1b).
3. What substrates and what conditions are used to keep the cells in good shape for AFM imaging?
Posted by: Edgar Arriaga | May 6, 2008 11:42 PM
According to authors the resolution in the lateral (xy-plane) direction is 1 nm, while the resolution in the vertical (z-plane) is .1 nm. This is while operating in contact mode in either air or a vacuum. I found it surprising the resolution did not improve when performed in a vacuum.
Posted by: Jonathan Dozier | May 7, 2008 08:50 PM
2. (I copied figure 2b into ImageJ and measured the height of the background signal at several points). The background has a standard deviation of about 20 nm, so we could determine a height difference of 60 nm.
Posted by: Greg Wolken | May 8, 2008 10:20 AM
According to question 3, the authors use a substrate of polyornithine and laminin, because healthy DRG neurons can attach on this substrate very well. Thus, when you perform the AFM scanning, the cell will not be easy to move or destroy. Besides, they use tapping mode to image the cell. Compared to contact mode, tapping mode doesn't contact to cell surface at all the scanning times, so it cause less damage to cell surface. In the article, they also mentioned that AFM operation in fluids minimizes damage to the cells.
Posted by: Yu-Shen Lin | May 8, 2008 10:32 AM