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2026-06-10 @ CHESS 7b2

First CHESS beam time of the 2026-2 run cycle.

Goals

  • DHFR-Fol-NADP diffuse map at 277 K
  • DHFR-Fol-NADP multi-temperature data collection (following Hekstra lab's published protocol).
  • Screening Mac1 hits obtained during Oryx training last week.

Participants

Steve M, Katie L, & Xiaokun P from Ando lab; support from John I & Tricia C at CHESS

Data

Root directory at CHESS: /nfs/chess/raw/2026-2/id7b2/meisburger/20260610

Root directory on OSN: s3://diffuse-chess-public/20260610

Beamline setup

parameter value notes
X-ray energy 14 keV @ 0.01% bandwidth Si 111 channel cut mono inserted
Beam size 100 µm x 100 µm (initially) Slit-defined, no CRL. Adjusted to match crystal size when noted, below.
Flux 7.8 x 1010 ph/s ICol ~36,000 / 0.1 s (see CHESS 7b2 beamline notebook #3)
Background reduction On-axis mirror with Mo tube
Centering camera top-view and on-axis cameras Top view: 1.713 µm / pixel at 4x zoom ratio; On axis: 0.740 µm / pixel at 4x zoom ratio
Beamstop 700 µm diameter Mo disk suspended on mylar sheet semi-transparent
Data collection software "MX Collect" (python) & SPEC No changes since last time
Temperature control none (initially) For DHFR only, the Oxford cryostream was installed end-on

Steve arrived at 10 and set up the workspace. John and Tricia aligned the beam and optics and installed the cold stream. Steve re-measured the flux (noted above), optimized the beam profile, added steel shielding and Pb tape to clean up background scattering.

Took a 1s exposure with no pin (just air) to assess background.

Subdirectory: setup

prefix φ0 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
air_312 0 0 1 1 100 185 14

Looks pretty good.

Samples

The following samples were grown in 24-well hanging-drop vapor diffusion trays:

Name Sample Well composition Drop composition Notes
Mac1 (P43 space group) SARS CoV2 NSP3 macrodomain and seed stock from UCSF. 40 mg/mL Mac1 in 150 mM NaCl, 20 mM Tris pH 8, 5% glycerol 30% (w/vol) PEG 3000 + 100 mM CHES (pH 9.5) 2 µL protein + 1 µL well solution + 1 µL seeds (undiluted) 24-well hanging-drop vapor diffusion tray (2/10/2026). See Katie L Ando Lab notebook p. 32
'' '' Hampton Crystal Screen HT (pdf) 1.5 µL protein + 1 µL well solution + 0.5 µL seed stock 96 well sitting drop vapor diffuse tray set up during Oryx robot training (6/2/2026). See Katie L Ando Lab notebook p. ??
Lysozyme Hen egg lysozyme, 50 mg/mL in NaOAc 0.9 M NaCl, 100 mM NaOAc pH 4.2 2 µL protein + 2 µL well solution 24-well hanging-drop vapor diffusion tray set up by Min P for practice (10/17/2025).
DHFR-Folate-NADP E. coli dihydrofolate reductase expressed and purified at Cornell. Dialyzed in 20 mM imidazole pH 7.0 with 1 mM folic acid and concentrated to 35 mg/mL. NADP+ added in 3:1 molar excess (final concentrations: 31.5 mg/mL DHFR, 6.3 mM NADP) 15% PEG 400, 100 mM MnCl2, 20 mM imidazole pH 7.0 1.5 µL protein + 1.5 µL well solution + 1 µL seed stock DHFR Tray #4 row A (5/8/2026). Sixteen crystals were looped in the cold room under red light and transported to CHESS at 4 deg C. See Steve's Ando Lab Notebook #3, pp. 73, 76, 77
  • mac1_b6
    Mac1 crystal from well A6 of Katie L's tray dated 2/10/2026. Katie harvested from well B6, which was not photographed, but had the same conditions as A6 (except that A6 had agarose added to the drop). Well solution: 38% PEG, 100 mM CHES pH 9.5. Drop: 2 µL protein + 1 µL well solution + 1 µL seed stock.

  • lysozyme_a4
    Lysozyme crystal mounted on the beamline, from well A4 of Min P's practice tray, dated 10/17/2025. Well solution: 0.9 M NaCl, 100 mM Na acetate pH 4.2. Drop: 2 µL protein + 2 µL well solution

  • mac1_screen_b3
    Mac1 crystals from well B3 of Katie L's screening tray, dated 6/2/2026. Precipitant solution: 0.2 M Ammonium sulfate, 0.1 M Na cacodylate trihydrate pH 6.5, 30% w/v PEG 8,000 Drops contain: .1, .08, .04 seed (top), .15, .08, .04 seed (bottom)

  • mac1_screen_b5
    Mac1 crystals from well B5 of Katie L's screening tray, dated 6/2/2026. Precipitant solution: 0.2 M Li sulfate monohydrate, 0.1 M TRIS hydrochloride pH 8.5, 30% w/v PEG 4,000 Drops contain 1.5 µL protein + 1 µL precipitant solution + 0.5 µL seed stock.

  • mac1_screen_b10
    Mac1 crystals from well B10 of Katie L's screening tray, dated 6/2/2026. Precipitant solution: 0.2 M Na acetate trihydrate, 0.1 M TRIS hydrochloride pH 8.5, 30% w/v PEG 4,000. Drops contain 1.5 µL protein + 1 µL precipitant solution + 0.5 µL seed stock.

  • mac1_screen_g8
    Mac1 crystals from well G5 of Katie L's screening tray, dated 6/2/2026. Precipitant solution: 0.1 M NaCl, 0.1 M HEPES pH 7.5, 1.6 M Ammonium sulfate. Drops contain 1.5 µL protein + 1 µL precipitant solution + 0.5 µL seed stock.

  • dhfr_fol_nadp_a2
    DHFR-Folate crystals from well A2 of Steve's DHFR Tray #4, dated 5/8/2026. Well solution: 15% PEG 400, 100 mM MnCl2, 20 mM imidazole pH 7.0. Drop: 1.5 µL protein + 1.5 µL well solution + 1 µL seed stock (10-fold dilution)

  • dhfr_fol_nadp_a3
    DHFR-Folate crystals from well A3 of Steve's DHFR Tray #4, dated 5/8/2026. Well solution: 15% PEG 400, 100 mM MnCl2, 20 mM imidazole pH 7.0. Drop: 1.5 µL protein + 1.5 µL well solution + 1 µL seed stock (100-fold dilution)

  • dhfr_fol_nadp_a5
    DHFR-Folate crystals from well A5 of Steve's DHFR Tray #4, dated 5/8/2026. Well solution: 15% PEG 400, 100 mM MnCl2, 20 mM imidazole pH 7.0. Drop: 1.5 µL protein + 1.5 µL well solution + 1 µL seed stock (10,000-fold dilution)

  • dhfr_fol_nadp_a6
    DHFR-Folate crystals from well A6 of Steve's DHFR Tray #4, dated 5/8/2026. Well solution: 15% PEG 400, 100 mM MnCl2, 20 mM imidazole pH 7.0. Drop: 1.5 µL protein + 1.5 µL well solution + 1 µL seed stock (100,000-fold dilution)

Data collection

First, use lysozyme and mac1 to test radiation damage.

1. Lysozyme

Katie looped a ~400 µm lysozyme crystal from well A4 of tray dated 10/17/2025.

Subdirectory: lysozyme

Snapped images every 30˚ using the on-axis camera, prefix: lys1_oac_zoom1.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
lys1_313 0 720 0.1 7200 0.01 100 185 14
lys1_bg_314 0 720 1 720 0.1 100 185 14
xia2 processing
lys1_313
scan 313
Mosaic spread 0.008
Resolution 1.11
Unit Cell [79.03, 79.03, 38.0, 90.0, 90.0, 90.0]
Image range [1, 7200]
Completeness 94.3
Multiplicity 46.3
I/sigma 22.4
Rpim 0.012
Wilson B factor 18.8
Space group P 43 21 2

2. Mac1

Katie looped a Mac1 crystal from well B6 of tray dated 2/10/2026 using a 200 µm loop. The sleeve and loop have some droplets / PEG skin, might be a problem for diffuse map.

Subdirectory: mac1

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
mac1_1_315 0 720 0.1 7200 0.01 47.1 185 14
mac1_1_bg_316 0 720 1 720 0.1 47.1 185 14
xia2 processing
mac1_1_315
scan 315
Mosaic spread 0.013
Resolution 1.07
Unit Cell [89.1, 89.1, 40.15, 90.0, 90.0, 90.0]
Image range [1, 7200]
Completeness 90.7
Multiplicity 22.8
I/sigma 15.6
Rpim 0.016
Wilson B factor 13.87
Space group P 43

3. DHFR-Folate-NADP

Steve placed the cold stream end-on and set the temperature to 277 K. The hutch was darkened and centering light was replaced with amber filtered LED source.

Steve mounted DHFR sample #1 (well A2) at 277 K. Slits were set to 100 x 100 µm.

Subdirectory: dhfr/dhfr_1

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_1_oac_zoom4.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_1_277K_317 0 360 0.1 3600 0.01 100 185 14

Next, ramp up to 310 K at 2 ˚C/min, collect another dataset.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_1_310K_318 0 360 0.1 3600 0.01 100 185 14

The protein looks pretty dried out.

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_1_310K_oac_zoom4.

Ramp back down to 277 K at 2 ˚C/min. Was this reversible?

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_1_277K_319 0 360 0.1 3600 0.01 100 185 14

After cooling, the capillary had a lot of condensation on it. Clearly there are some temperature differentials inside the capillary that need to be optimized. Will revisit multi-temperature systematically at the end.

xia2 processing
dhfr_1_277K_317
scan 317
Mosaic spread 0.064
Resolution 1.25
Unit Cell [34.19, 45.27, 98.85, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 99.6
Multiplicity 12.9
I/sigma 6.5
Rpim 0.055
Wilson B factor 12.34
Space group P 21 21 21

4. DHFR-Folate-NADP

Steve mounted DHFR sample #2 (well A2) at 277 K. This is a long crystal sitting at an angle on the loop.

Subdirectory: dhfr/dhfr_2

Slits changed to 50 x 50 µm. Vector scan with 20 ms exposures, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_2_277K_320 0 360 0.1 3600 0.02 100 185 14
dhfr_2_277K_321 0 360 0.1 3600 0.02 100 185 14
dhfr_2_277K_bg_322 0 360 1 360 0.2 100 185 14

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_2_277K_oac_zoom4.

xia2 processing
dhfr_2_277K_320
scan 320
Mosaic spread 0.046
Resolution 1.28
Unit Cell [34.25, 45.42, 98.83, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 100.0
Multiplicity 13.0
I/sigma 8.1
Rpim 0.073
Wilson B factor 13.05
Space group P 21 21 21

5. DHFR-Folate-NADP

Steve mounted DHFR sample #3 (well A2) at 277K. Crystal is a ~100x50 µm rod.

Subdirectory: dhfr/dhfr_3

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_3_277K_oac_zoom4.

Slits changed to 100 x 100 µm. Regular scan with 10 ms exposures, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_3_277K_323 0 360 0.1 3600 0.01 100 185 14
dhfr_3_277K_324 0 360 0.1 3600 0.01 100 185 14
dhfr_3_277K_bg_325 0 360 1 360 0.1 100 185 14
xia2 processing
dhfr_3_277K_323
scan 323
Mosaic spread 0.033
Resolution 1.23
Unit Cell [34.28, 45.52, 98.81, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 100.0
Multiplicity 12.7
I/sigma 5.6
Rpim 0.059
Wilson B factor 11.7
Space group P 21 21 21

6. DHFR-Folate-NADP

Steve mounted DHFR sample #4 (well A2) at 277 K. Crystal is ~100 x 25 µm.

Subdirectory: dhfr/dhfr_4

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_4_277K_oac_zoom4.

Slits changed to 100 x 50 µm (h x v). Regular scan with 10 ms exposures, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_4_277K_326 0 360 0.1 3600 0.01 100 185 14
dhfr_4_277K_327 0 360 0.1 3600 0.01 100 185 14
dhfr_4_277K_bg_328 0 360 1 360 0.1 100 185 14
xia2 processing
dhfr_4_277K_326
scan 326
Mosaic spread 0.027
Resolution 1.19
Unit Cell [34.27, 45.48, 98.83, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 99.1
Multiplicity 12.5
I/sigma 5.9
Rpim 0.06
Wilson B factor 12.12
Space group P 21 21 21

beam tune up

ICol counts increased from ~15,000 / 0.1s to ~23,000 / 0.1s (slits 100 x 50 µm).

7. DHFR-Folate-NADP

Steve mounted DHFR sample #5 (well A2) at 277 K. A small blucky crystal? Crytsal oriented perpendicular to the rotation axis.

Subdirectory: dhfr/dhfr_5

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_5_277K_oac_zoom4.

Slits changed to 50 x 100 µm (h x v). Regular scan with 10 ms exposures, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_5_277K_329 0 360 0.1 3600 0.01 100 185 14
dhfr_5_277K_330 0 360 0.1 3600 0.01 100 185 14
dhfr_5_277K_bg_331 0 360 1 360 0.1 100 185 14

multiple lattices

45.6% indexed

xia2 processing
dhfr_5_277K_329
scan 329
Mosaic spread 0.037
Resolution 1.28
Unit Cell [34.29, 45.51, 98.81, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 100.0
Multiplicity 13.0
I/sigma 5.5
Rpim 0.062
Wilson B factor 12.04
Space group P 21 21 21

8. DHFR-Folate-NADP

Steve mounted sample #6 (well A2) at 277 K. Crystal is ~100 x ~35 µm.

Subdirectory: dhfr/dhfr_6

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_6_277K_oac_zoom4.

Slits changed to 100 x 50 µm (h x v). Regular scan with 10 ms exposures, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_6_277K_332 0 360 0.1 3600 0.01 100 185 14
dhfr_6_277K_333 0 360 0.1 3600 0.01 100 185 14
dhfr_6_277K_bg_334 0 360 1 360 0.1 100 185 14
xia2 processing
dhfr_6_277K_332
scan 332
Mosaic spread 0.018
Resolution 1.14
Unit Cell [34.29, 45.51, 98.8, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 96.3
Multiplicity 12.0
I/sigma 6.8
Rpim 0.045
Wilson B factor 12.5
Space group P 21 21 21

9. DHFR-Folate-NADP

Steve mounted DHFR sample #7 (well A2) at 277 K. Crystal is ~100 x 50 µm, oriented diagonally.

Subdirectory: dhfr/dhfr_7

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_7_277K_oac_zoom4.

Slits changed to 100 x 100 µm (h x v). Regular scan with 10 ms exposures, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_7_277K_335 0 360 0.1 3600 0.01 100 185 14
dhfr_7_277K_336 0 360 0.1 3600 0.01 100 185 14
dhfr_7_277K_bg_337 0 360 1 360 0.1 100 185 14
xia2 processing
dhfr_7_277K_335
scan 335
Mosaic spread 0.009
Resolution 1.16
Unit Cell [34.28, 45.48, 98.8, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 100.0
Multiplicity 11.9
I/sigma 6.7
Rpim 0.048
Wilson B factor 12.65
Space group P 21 21 21

10. DHFR-Folate-NADP

Steve mounted DHFR sample #8 (well A2) at 277 K. Crystal is ~200 x 50 x 10 µm long (thin blade shape).

Subdirectory: dhfr/dhfr_8

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_8_277K_oac_zoom4.

Slits changed to 50 x 50 µm (h x v). Vector scan over ~150 µm with 20 ms exposures, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_8_277K_338 0 360 0.1 3600 0.02 100 185 14
dhfr_8_277K_339 0 360 0.1 3600 0.02 100 185 14
dhfr_8_277K_bg_340 0 360 1 360 0.2 100 185 14
xia2 processing
dhfr_8_277K_338
scan 338
Mosaic spread 0.217
Resolution 1.37
Unit Cell [34.32, 45.56, 98.99, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 97.9
Multiplicity 13.4
I/sigma 6.9
Rpim 0.086
Wilson B factor 13.61
Space group P 21 21 21

11. DHFR-Folate-NADP

Steve mounted DHFR sample #9 (large crystal from well A5) at 277 K. The crystal is ~500 x 100 x 50 µm.

Subdirectory: dhfr/dhfr_9

Snapped images every 30˚ using the on-axis camera (2x zoom ratio), prefix: dhfr_9_277K_oac_zoom2.

Slits changed to 100 x 100 µm (h x v). Vector scan over ~430 µm with 20 ms exposures and 720 degrees, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_9_277K_341 0 720 0.1 7200 0.02 100 185 14
dhfr_9_277K_342 0 720 0.1 7200 0.02 100 185 14
dhfr_9_277K_bg_343 0 720 1 720 0.2 100 185 14
xia2 processing
dhfr_9_277K_341
scan 341
Mosaic spread 0.035
Resolution 1.03
Unit Cell [34.18, 45.18, 98.94, 90.0, 90.0, 90.0]
Image range [1, 7200]
Completeness 80.3
Multiplicity 22.5
I/sigma 13.7
Rpim 0.019
Wilson B factor 12.9
Space group P 21 21 21

12. DHFR-Folate-NADP

Steve mounted DHFR sample #10 (thin long crystal from well A6) at 277 K.

Subdirectory: dhfr/dhfr_10

Snapped images every 30˚ using the on-axis camera (4x zoom ratio), prefix: dhfr_10_277K_oac_zoom4.

Slits changed to 100 x 50 µm (h x v). Vector scan over ~340 µm with 20 ms exposures and 720 degrees, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_10_277K_344 0 720 0.1 7200 0.02 100 185 14
dhfr_10_277K_345 0 720 0.1 7200 0.02 100 185 14
dhfr_10_277K_bg_346 0 720 1 720 0.2 100 185 14
xia2 processing
dhfr_10_277K_344
scan 344
Mosaic spread 0.021
Resolution 1.05
Unit Cell [34.25, 45.4, 98.86, 90.0, 90.0, 90.0]
Image range [1, 7200]
Completeness 81.4
Multiplicity 23.5
I/sigma 14.3
Rpim 0.019
Wilson B factor 12.88
Space group P 21 21 21

13. DHFR-Folate-NADP

Steve mounted DHFR sample #11 (~200 µm long crystal from well A3) at 277 K.

Subdirectory: dhfr/dhfr_11

Snapped images every 30˚ using the on-axis camera (4x zoom ratio), prefix: dhfr_11_277K_oac_zoom4.

Slits set to 100 x 50 µm (h x v). Vector scan over ~150 µm with 20 ms exposures and 360 degrees, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_11_277K_347 0 360 0.1 3600 0.02 100 185 14
dhfr_11_277K_348 0 360 0.1 3600 0.02 100 185 14
dhfr_11_277K_bg_349 0 360 1 360 0.2 100 185 14
xia2 processing
dhfr_11_277K_347
scan 347
Mosaic spread 0.016
Resolution 1.07
Unit Cell [34.25, 45.43, 98.85, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 84.3
Multiplicity 11.9
I/sigma 9.6
Rpim 0.033
Wilson B factor 12.4
Space group P 21 21 21

14. DHFR-Folate-NADP

Steve mounted DHFR sample #12 (~100 µm long crystal from well A3) at 277 K.

There is a big drop of water on the surface of the capillary, but it shouldn't intercept the direct beam (however may block diffraction at certain angles).

Subdirectory: dhfr/dhfr_12

Snapped images every 30˚ using the on-axis camera (4x zoom ratio), prefix: dhfr_12_277K_oac_zoom4.

Slits set to 100 x 50 µm (h x v). Regular scan with 10 ms exposures and 360 degrees, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_12_277K_350 0 360 0.1 3600 0.01 100 185 14
dhfr_12_277K_351 0 360 0.1 3600 0.01 100 185 14
dhfr_12_277K_bg_352 0 360 1 360 0.1 100 185 14
xia2 processing
dhfr_12_277K_350
scan 350
Mosaic spread 0.007
Resolution 1.13
Unit Cell [34.27, 45.47, 98.81, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 92.7
Multiplicity 12.2
I/sigma 7.1
Rpim 0.046
Wilson B factor 12.9
Space group P 21 21 21

15. DHFR-Folate-NADP

Steve mounted DHFR sample #13 (~100 µm long crystal from well A3) at 277 K.

Huge blob of gunk came along for the ride. Not ideal for background subtraction.

Subdirectory: dhfr/dhfr_13

Snapped images every 30˚ using the on-axis camera (4x zoom ratio), prefix: dhfr_13_277K_oac_zoom4.

Slits set to 100 x 50 µm (h x v). Vector scan with 20 ms exposures and 360 degrees, repeated for radiation damage assessment (the second scan could be merged if undamaged).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_13_277K_353 0 360 0.1 3600 0.02 100 185 14
dhfr_13_277K_354 0 360 0.1 3600 0.02 100 185 14
dhfr_13_277K_bg_355 0 360 1 360 0.2 100 185 14
dhfr_13_277K_bg_356 0 360 1 360 0.2 100 185 14
xia2 processing
dhfr_13_277K_353
scan 353
Mosaic spread 0.077
Resolution 1.51
Unit Cell [34.26, 45.44, 98.83, 90.0, 90.0, 90.0]
Image range [1, 3600]
Completeness 99.4
Multiplicity 10.8
I/sigma 12.7
Rpim 0.946
Wilson B factor 14.17
Space group P 21 21 21

Setup change

Cold stream removed. Switch to Mac1 screening.

16. Mac1

Xiakun looped a crystal from B3 Bottom drop of katie's 6/2/2026 Mac1 P43 screening tray (Xtal-HT). Used 100 µm loop w/ 10 µL well sleeve. It looked like 2 crystals inside the loop.

Subdirectory: mac1/mac1_B3b

Slits set to 50 x 50 µm. Regular scan of 360 degrees.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
mac1_B3b_357 0 360 0.5 720 0.02 100 185 14

Snapped images every 30˚ using the on-axis camera, prefix: mac1_B3b_oac_zoom4.

xia2 processing
mac1_B3b_357
scan 357
Mosaic spread 0.092
Resolution 1.53
Unit Cell [89.12, 89.12, 40.36, 90.0, 90.0, 90.0]
Image range [1, 720]
Completeness 100.0
Multiplicity 13.8
I/sigma 4.4
Rpim 0.079
Wilson B factor 14.55
Space group P 41

17. Mac1

Katie looped a crystal from B5 top drop of the same tray with 100 µm loop, 10 µL well solution in the sleeve. Crystal was largest & squarest in drop.

Subdirectory: mac1/mac1_B5t

Snapped images every 30˚ using the on-axis camera, prefix: mac1_B5t_oac_zoom4.

Slits set to 100 x 100 µm.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
mac1_B5t_358 0 360 0.5 720 0.02 100 185 14
mac1_B5t_359 0 360 0.5 720 0.02 100 225 14

multiple lattices

20.7% indexed

xia2 processing
mac1_B5t_359
scan 359
Mosaic spread 0.427
Resolution 1.61
Unit Cell [89.12, 89.12, 40.27, 90.0, 90.0, 90.0]
Image range [1, 720]
Completeness 100.0
Multiplicity 13.8
I/sigma 3.2
Rpim 0.097
Wilson B factor 13.15
Space group P 41

18. Mac1

Katie looped another crystal from the same drop that was more rod-like, but too small for the 100 µm loop it was in, so iat appeared to be moving around in the loop.

Subdirectory: mac1/mac1_B5t_rod

Snapped images every 30˚ using the on-axis camera, prefix: mac1_B5t_rod_oac_zoom4.

Slits set to 100 x 100 µm.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
mac1_B5t_rod_360 0 360 0.5 720 0.02 100 225 14

Crystal slid while rotating but can still be indexed.

xia2 processing
mac1_B5t_rod_360
scan 360
Mosaic spread 0.387
Resolution 2.2
Unit Cell [88.86, 88.86, 40.18, 90.0, 90.0, 90.0]
Image range [1, 720]
Completeness 100.0
Multiplicity 24.3
I/sigma 1.2
Rpim 1.579
Wilson B factor 11.28
Space group P 41 2 2

19. Mac1

Katie looped something -- PEG skin? from bottom drop B10 of the same tray with 100 µm loop.

Subdirectory: mac1/mac1_B10b

Slits set to 100 x 100 µm. Collect from three locations: centered (361), near the base (362), and near the top (363).

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
mac1_B10b_361 0 360 0.5 720 0.02 100 225 14
mac1_B10b_2_362 0 360 0.5 720 0.02 100 225 14
mac1_B10b_3_363 0 360 0.5 720 0.02 100 225 14

The 2nd and 3rd datasets had spots in some frames. might not be enough for unit cell determination. The 2nd dataset did not index in xia2. The 3rd dataset processed to completion.

xia2 processing
mac1_B10b_3_363
scan 363
Mosaic spread 0.015
Resolution 2.36
Unit Cell [89.19, 89.19, 40.17, 90.0, 90.0, 90.0]
Image range [1, 720]
Completeness 100.0
Multiplicity 13.9
I/sigma 1.6
Rpim 0.289
Wilson B factor 13.46
Space group P 41

20. Mac1

Xiaokun looped at ~25 µm crystal from the bottom drop of B10 of the same tray.

Subdirectory: mac1/mac1_B10b_square

Snapped images every 30˚ using the on-axis camera, prefix: mac1_B10b_square_oac_zoom4.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
mac1_B10b_square_364 0 360 0.5 720 0.02 100 225 14
mac1_B10b_square_365 0 360 0.5 720 0.05 100 225 14
xia2 processing
mac1_B10b_square_364
scan 364
Mosaic spread 0.062
Resolution 1.98
Unit Cell [89.1, 89.1, 40.2, 90.0, 90.0, 90.0]
Image range [1, 720]
Completeness 100.0
Multiplicity 13.0
I/sigma 1.9
Rpim 2.559
Wilson B factor 13.27
Space group P 41

21. Mac1

Xiaokun looped a crystal from the bottom drop of G8 of the same tray with a 75 µm loop.

Subdirectory: mac1/mac1_G8

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
mac1_G8b_366 0 360 0.5 720 0.02 100 185 14
xia2 processing
mac1_G8b_366
scan 366
Mosaic spread 0.017
Resolution 1.74
Unit Cell [89.06, 89.06, 40.3, 90.0, 90.0, 90.0]
Image range [1, 720]
Completeness 100.0
Multiplicity 13.9
I/sigma 3.2
Rpim 0.131
Wilson B factor 14.17
Space group P 41

Setup change

Steve set up again for DHFR experiments, with the cold stream end-on at 277 K, and the hutch darkened & amber light for centering.

22. DHFR-Folate-NADP

The plan is to (hopefully) collect multi-temperature data from DHFR, using the remaining 3 samples. I hope to answer the questions:

  • To avoid condensation / dehydration, is it important to ramp slowly? We previously saw dehydration at 2 ˚C / minute, although this was the rate used by the Hekstra lab previously.
  • Are changes reversible (as measured by mosaicity, resolution / B-factor)?

Steve loaded DHFR sample #14 (well A3) at 277 K, which is a small rod in a dt loop. Based on appearance, there might be two crystals present. For better temperature regulation (or possibly less turbulance around the sleeve), the cold stream was advanced so that the tip of the sleeve was inside the nozzle.

Subdirectory: dhfr/dhfr_14

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_14_277K_oac_zoom4.

Beam size set to 50 x 50 µm. At each temperature, collect a dataset with 1/4 the usual dose (180 degrees, 47% transmission), since we'll be repeating the data collection at multiple temperatures: 277 K, 295 K, 310 K, 295 K, and 277 K.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_14_277K_367 0 180 0.1 1800 0.01 47.1 185 14
dhfr_14_277K_bg_368 0 180 1 180 0.1 47.1 185 14

Ramp up to 295 K at 1 ˚C / min.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_14_295K_369 0 180 0.1 1800 0.01 47.1 185 14
dhfr_14_295K_bg_370 0 180 1 180 0.1 47.1 185 14

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_14_295K_oac_zoom4.

Ramp up to 310 K at 1 ˚C / min.

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_14_310K_oac_zoom4.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_14_310K_371 0 180 0.1 1800 0.01 47.1 185 14
dhfr_14_310K_bg_372 0 180 1 180 0.1 47.1 185 14

Ramp back down to 295 K at 1 ˚C / min.

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_14_295K_2_oac_zoom4.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_14_295K_2_373 0 180 0.1 1800 0.01 47.1 185 14
dhfr_14_295K_2_bg_374 0 180 1 180 0.1 47.1 185 14

Ramp back down to 277 K at 1 ˚C / min.

No condensation observed in the tube!

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_14_277K_2_oac_zoom4.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_14_277K_2_375 0 180 0.1 1800 0.01 47.1 185 14
dhfr_14_277K_2_bg_376 0 180 1 180 0.1 47.1 185 14

Conclusions:

  • 1 ˚C / minute is a good speed and/or placing the sleeve inside the cold stream helps maintain more uniform temperatures.
  • Temperature effects are mostly reversible (i.e. Wilson B-factor increases with temperature, and goes back down again upon cooling -- resolution does not change much between first and last datasets).
xia2 processing
dhfr_14_277K_367 dhfr_14_295K_369 dhfr_14_310K_371 dhfr_14_295K_2_373 dhfr_14_277K_2_375
scan 367 369 371 373 375
Mosaic spread 0.108 0.018 0.285 0.043 0.061
Resolution 1.6 1.67 2.43 1.66 1.78
Unit Cell [34.1, 44.66, 99.02, 90.0, 90.0, 90.0] [34.21, 44.88, 99.48, 90.0, 90.0, 90.0] [34.26, 44.53, 100.52, 90.0, 90.0, 90.0] [34.32, 45.42, 98.94, 90.0, 90.0, 90.0] [34.14, 44.75, 99.37, 90.0, 90.0, 90.0]
Image range [1, 1800] [1, 1800] [1, 1800] [1, 1800] [1, 1800]
Completeness 100.0 100.0 100.0 100.0 100.0
Multiplicity 6.5 6.6 6.4 6.6 6.6
I/sigma 3.3 5.3 4.7 4.6 5.2
Rpim 0.111 0.098 0.151 0.104 0.103
Wilson B factor 14.08 20.23 42.18 18.07 21.1
Space group P 21 21 21 P 21 21 21 P 21 21 21 P 21 21 21 P 21 21 21

23. DHFR-Folate-NADP

Next, lets follow the Hekstra lab temperature protocol: 295 K, 310 K, 295 K, 280 K, 295 K.

Steve mounted DHFR sample #15 (from well A3) at 277 K, a long rod on a DT loop, perhaps 400 µm overall length.

Subdirectory: dhfr/dhfr_15

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_15_277K_oac_zoom4.

Ramp temperature to 295 K at 1 ˚C / minute (18 minutes)

Beam size set to 50 x 50 µm. Vector scan over the length of the crystal using low dose (10 ms exposures, 360 degrees, and 47% transmission). Do this at each temperature, and then ramp to the next at 1 ˚C / minute.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_15_295K_1_377 0 360 0.1 3600 0.01 47.1 185 14
dhfr_15_295K_1_bg_378 0 360 1 360 0.1 47.1 185 14
dhfr_15_310K_379 0 360 0.1 3600 0.01 47.1 185 14
dhfr_15_310K_bg_380 0 360 1 360 0.1 47.1 185 14
dhfr_15_295K_2_381 0 360 0.1 3600 0.01 47.1 185 14
dhfr_15_295K_2_bg_382 0 360 1 360 0.1 47.1 185 14
dhfr_15_280K_383 0 360 0.1 3600 0.01 47.1 185 14
dhfr_15_280K_bg_384 0 360 1 360 0.1 47.1 185 14
dhfr_15_295K_3_385 0 360 0.1 3600 0.01 47.1 185 14
dhfr_15_295K_3_bg_386 0 360 1 360 0.1 47.1 185 14

Some condensation on the capillary was visible in the top view camera upon cooling to 280 K. Upon dismounting the sample, I noticed that the capillary was not perfectly centered in the cold stream nozzle. Perhaps this was an issue. Next time I will more carefully center it.

Reproducibility of resolution and Wilson B-factor between replicates at 295 K was excellent this time.

xia2 processing
dhfr_15_295K_1_377 dhfr_15_310K_379 dhfr_15_295K_2_381 dhfr_15_280K_383 dhfr_15_295K_3_385
scan 377 379 381 383 385
Mosaic spread 0.015 0.053 0.049 0.047 0.046
Resolution 1.51 1.76 1.47 1.46 1.51
Unit Cell [34.24, 45.22, 99.13, 90.0, 90.0, 90.0] [34.24, 44.68, 100.11, 90.0, 90.0, 90.0] [34.34, 45.54, 98.84, 90.0, 90.0, 90.0] [34.29, 45.47, 98.84, 90.0, 90.0, 90.0] [34.33, 45.52, 98.86, 90.0, 90.0, 90.0]
Image range [1, 3600] [1, 3600] [1, 3600] [1, 3600] [1, 3600]
Completeness 100.0 100.0 100.0 100.0 100.0
Multiplicity 13.2 13.2 13.3 13.3 13.2
I/sigma 5.9 5.5 5.1 4.4 4.8
Rpim 0.071 0.074 0.076 0.08 0.077
Wilson B factor 18.37 25.89 16.7 15.89 17.28
Space group P 21 21 21 P 21 21 21 P 21 21 21 P 21 21 21 P 21 21 21

24. DHFR-Folate-NADP

With the final crystal, let's repeat the previous temperature series again using the faster ramp rate of 2 ˚C / minute.

Mounted DHFR sample #16 (well A3) at 277 K. This is a ~200 µm long rod in a DT loop.

First, temperature ramp to 295 K at 2 ˚C / minute (9 minutes).

Subdirectory: dhfr/dhfr_16

Snapped images every 30˚ using the on-axis camera, prefix: dhfr_16_277K_oac_zoom4.

Vector scan using 50 x 50 µm beam along the length of the crystal. Low-dose: 360 degrees, 10 ms exposures, 47% transmission.

prefix φ0 (deg.) φ1 (deg.) ∆φ (deg.) images ∆t (s) tf (%) d (mm) E (keV)
dhfr_16_295K_1_387 0 360 0.1 3600 0.01 47.1 185 14
dhfr_16_295K_1_bg_388 0 360 1 360 0.1 47.1 185 14
dhfr_16_310K_389 0 360 0.1 3600 0.01 47.1 185 14
dhfr_16_310K_bg_390 0 360 1 360 0.1 47.1 185 14
dhfr_16_295K_2_391 0 360 0.1 3600 0.01 47.1 185 14
dhfr_16_295K_2_bg_392 0 360 1 360 0.1 47.1 185 14
dhfr_16_280K_393 0 360 0.1 3600 0.01 47.1 185 14
dhfr_16_280K_bg_394 0 360 1 360 0.1 47.1 185 14
dhfr_16_295K_3_395 0 360 0.1 3600 0.01 47.1 185 14
dhfr_16_295K_3_bg_396 0 360 1 360 0.1 47.1 185 14

Condensation started to appear in the top-view camera when cooling from 310 K to 295 K. It increased significantly upon cooling to 280 K.

Resolution, mosaicity, and Wilson B-factor are very consistent between 295 K replicates. At 310 K the mosaicity and B-factor increase and the unit cell changes too: slight decrease in the b-axis length, slight increase in the c-axis. This was not observed in the Hekstra lab paper (see Table S8 in the Supplementary information).

xia2 processing
dhfr_16_295K_1_387 dhfr_16_310K_389 dhfr_16_295K_2_391 dhfr_16_280K_393 dhfr_16_295K_3_395
scan 387 389 391 393 395
Mosaic spread 0.011 0.062 0.015 0.01 0.01
Resolution 1.43 1.66 1.46 1.46 1.5
Unit Cell [34.25, 45.33, 99.07, 90.0, 90.0, 90.0] [34.23, 44.77, 99.7, 90.0, 90.0, 90.0] [34.34, 45.55, 98.9, 90.0, 90.0, 90.0] [34.3, 45.49, 98.83, 90.0, 90.0, 90.0] [34.33, 45.51, 98.89, 90.0, 90.0, 90.0]
Image range [1, 3600] [1, 3600] [1, 3600] [1, 3600] [1, 3600]
Completeness 100.0 100.0 100.0 100.0 100.0
Multiplicity 13.3 13.2 13.3 13.3 13.2
I/sigma 6.6 5.7 6.2 7.9 6.3
Rpim 0.065 0.065 0.067 0.067 0.068
Wilson B factor 17.61 23.06 18.5 17.47 18.94
Space group P 21 21 21 P 21 21 21 P 21 21 21 P 21 21 21 P 21 21 21

Done!

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