Mass Spectrometry Imaging
- Page ID
- 290691
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Mass spec imaging – lesson plan summary
- Finish MALDI worksheet from last class (10 min)
- Short lecture on:
- MALDI (summarize method, with schematic)
- SIMS
- DESI
- Compare the three methods – ACTIVE PART
- Applications to mass spec imaging – ACTIVE PART
- Brief look at leaf and petal paper together on projector
Comparing MS imaging methods:
We built a chart on the board of the three methods:
- Give students the rows, and let them try to fill in the details
|
|
Ambient |
Vacuum |
Vacuum |
|
|
DESI |
MALDI |
SIMS |
|
Spatial Res |
150 um |
10 um |
0.1 um |
|
Soft or hard |
Soft |
Soft |
Hard |
|
Sensitivity (high/low) |
Lower? |
Lower? |
Higher? |
|
Other |
Non-destructive (can reuse sample) |
Good for proteins. Not good for small molecules. |
Deeper penetration. |
My notes:
Dozens of ambient ionization options:
Next, we briefly looked at this paper to see what they did –
Students pull it up on their laptops
J. Agric. Food Chem., 2013, 61(31), pp 7477–7487
https://pubs.acs.org/doi/full/10.1021/jf4011998
Q: What MS imaging technique did they use?
Ambient or vacuum?
Resolution achieved?
Why might they have done it this way?
Final Activity (15 min):
- Had students pull up a computer and get online
- Search for "mass spec imaging" for a topic they are interested in
- e.g. biomedical, drug distribution, brain
- e.g. art conservation, forensic science
- e.g. food or agriculture
- Find a paper
- Which ionization method do they use, and why?
- How was the sample prepared (live, fixed, stored)?
- Last 5 - 10 min, have some students share with the class what they found
This was fun! Students were very engaged and excited to find such cool science.
Contributors and Attributions
- Rebecca Pompano, University of Virginia (rrp2z@virginia.edu)
- Sourced from the Analytical Sciences Digital Library