Collecting CEST Data

Collecting CEST Data

1. Open TopSpin >= 3.2.X
2. Edit temperature
   1. “edte”
3. Create a dataset and collect a NHSQC to check resolution and NS
4. Type “edpy”, select n15cest_gb.py.
5. Click “execute” and hit “ok”.
6. Carrier Positions
   1. 1H water pos. (O1) = 3290.987 Hz (this can be changed)
   2. 15N carrier pos = 118 ppm
   3. 13C carrier pos = 118ppm (pseudo dimension)
7. Click “Ok”
8. Calibrated pulse values:
   1. 1H hard pulse = 10.25us @ -7.558748 dB (can be changed)
   2. 15N hard pulse = 35us @ -19.0309 dB
   3. 13C hard pulse = 12us @ -18.60338 dB
9. Click “Ok”
10. Values related to the weak B1 irradiation:
    1. 15N weak B1 field = 25 Hz (can be changed)
    2. Upfield irradiation offset limit = 100 ppm (can be changed)
    3. Downfield irradiation offset limit = 140 ppm (can be changed)
    4. Offset step size = 25 Hz (can be changed)
11. Click “Ok”
12. The experiment dataset will now be created. F1 is the pseudo dimension with the TD being the # of offsets that will be collected. The delays for these offsets can be found it FQLIST/FQ3LIST/n15cest_offset_std. This list name is overwritten each time a new CEST experiment is created so it is best to rename.
13. Edit F3 and F2 TDs.
14. DS must be >= 32.
15. NS must be >= 2.
16. Edit routing.
17. Click “Edit” for CPDPRG, change 90x240y90x to 90x_240y_90x
18. Make sure P50, P51, and P52 are all 500us
19. Calculate receiver gain
    1. “rga”
20. Edit D2 (t1 time)
21. Must also edit D3 so that D3 > D2.
22. Check ZGOPTNS
23. “zg”
24. The planes can be checked with “XFB”
    1. “xfb s23” plane 1
25. Also, collecting the first plane is advisable.