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Storage and imaging systems

 

 

The HTX lab is equipped with two imaging systems :

  • 4degC    RockImager (Formulatrix, Inc., U.S.) 500 plates capacity, visible light only
  • 20degC  RockImager (Formulatrix, Inc., U.S.) 1000 plates capacity, visible/UV light

 

The standard imaging schedule is (days after setup + 1-2 day tolerance) :

  • 1 day
  • 3 days
  • 7 days (vis+UV, if UV schedule selected)
  • 15 days
  • 33 days
  • 61 days
  • 87 days (vis+UV, if UV schedule selected)

Imaging times may slightly vary depending on the workload in the imaging systems. However, if an inspection is skipped, feel free to contact the HTX lab staff. Status of the inspection schedule can be checked in "My Xtal plates", see tutorial.

 

Plates will be kept in the imaging system until the last scheduled inspection is performed. Additional imaging can be requested but will be granted according to the imager's workload. Plates can be removed at any time from the robot upon demand. After the inspection period, the lab staff will store the plates on the storage shelves of the HTX crystallization rooms for user pick-up :

- at 20 degC : CIBB, basement, room S06a

- at 4 degC : CIBB, basement, cold room S11 (white cabinet)

 

Expired plates will be kept for one year after crystallization run

All experimental parameters are kept for a minimum of 7 years. High resolution images are available online for a minimum of two years. After this time they are archived and can be recovered upon user's request. The CRIMS server is under regular automated back up policy.

Feel free to contact the HTX lab staff for further information (This email address is being protected from spambots. You need JavaScript enabled to view it.).

 

The Formulatrix RockImager at 20°C

The Formulatrix RockImager at 4°C

 

UV light imaging (available at 20degC only)

UV imaging is now provided by the imaging robot at 20degC at the HTX lab. Ultra-violet light can be used to differentiate salt crystal from protein crystal thanks to the intrinsic fluorescence of tryptophan residue and in some extend to tyrosine and phenylalanine.

Fluorescence of a protein sample is influenced by several parameters(1):
• Signal strength depends on proportion of tryptophan in the protein.
• Haem-containing proteins are self-quenching.
• Some chemicals may interfere with fluorescence: e.g. nitrates, iron ions or cobalt ions are known to be quenching agents.
• Absence of UV signal doesn't necessary imply that the crystal is a salt crystal.

 

While doing your crystallization request, the schedule “Imaging Robot 20 +UV” provides two UV inspections in addition of the standard visible inspections at days 7 and 87. Single plate or single drop imaging can be performed upon request, please contact us at This email address is being protected from spambots. You need JavaScript enabled to view it..

 

UV-light examples

 

Reference

1. Desbois et al. Acta Cryst. (2013). 69(Pt 2): 201–208.