Edited on Sep 25, 2009

The marcsc "Cryogenic Sample Changer"


The marcsc is an automated sample changing robot for X-ray crystallography. The instrument is fully integrated into the mardtb "desktop beamline", our multi-purpose goniometer. This integration makes the marcsc a compact, robust and very reasonably priced tool for high-throughput crystallography.

For more details, please have a look at the specifications.


Highlights:

marcsc sample changer attached to mardtb goniostat
  • High-throughput crystallography at the beamline or in the lab
    Designed as a completely integrated package with the mardtb advanced goniostat for single-crystal diffraction, the marcsc is a complete turn-key sample mounting system small enough not to crowd any synchrotron hutch or X-ray laboratory. The automated data collection reduces the fatigue on scientists, and allows testing larger numbers of crystals than previously possible.
  • Truly integrated with the goniostat
    Because the marcsc is an attachment to the mardtb, it takes advantage of the convenience of one-click automatic beam alignment. The whole system aligns itself to the X-ray beam automatically and has no realignment headaches or crashing problems of independent robotic arms.
  • Carousel of 19 samples in liquid nitrogen
    The removable carousel of 19 vials keeps samples safely in liquid nitrogen until they are called by the data collection program. A new carousel can be loaded by the user in just 30 seconds.
  • Mounting by automated computer control
    Samples are mounted for data collection by a system of computer driven motors. The user can be at the instrument, outside the hutch or X-ray laboratory, or at home!
  • Wet mount and wet retrieval
    Samples are mounted into the cold stream directly from a full vial of liquid nitrogen. With no room temperature exposure, crystals are kept safe in the cryogenic environment. The empty vial is replaced in the liquid nitrogen during data collection, and pulled out afterwards to accept the sample directly back into liquid nitrogen.
  • Accurate, automatic loop centering
    Optical images of the crystal from the mardtb CCD microscope, and a unique image processing algorithm, are used to align the loop in the X-ray beam. An active illumination system ensures constant lighting conditions independent of external light sources.
  • Barcode reader
    Sample identification is accomplished with a built-in barcode reader and magnetic caps with 2D barcode and alphanumeric number. The reader supports standard SPINE codes (2D data matrix with 12x12, 14x14 or 16x16 dots). Beware of ink-printed codes, though! While they are easily readable by the bar-code reader, the ink layer greatly reduces the holding force of the solenoid on the goniometer head, impeding safe sample handling.
  • Fully integrated software control
    Simple or sophisticated data collection protocols are all possible with the marcsc computer control. From screening to full data sets, the marcsc can automatically and reliably collect a full carousel of samples worth of data without user intervention. Useful crystal centering images are automatically logged for later verification.
  • Detector support
    The marcsc cooperates with the mar345 image plate detector, and Rayonix's SX-165 CCD and MX-225 CCD detectors.
Top view of marcsc
marcsc: mounting sample on goniometer head
marcsc: retrieving sample out of carousel
Carousel with 19 samples
marcsc: mounting sample on goniometer head
Barcode seen by reader

Specifications
General Features
  • Dedicated and highly optimized hardware for sample exchange
    All operations are optimized for highest possible throughput
    Sample exchange in approx. 2 minutes
    Perfect fit into mardtb desktop beamline, compact design
  • Liquid sample transfer
    Quick and precise tranfer of sample from storage system onto goniometer head
    Sample stays submerged in liquid nitrogen during entire transfer procedure
    Special transfer containers extend time beyond 60 sec. before nitrogen starts boiling
  • Usage of standard cryo vials
    Magnetic vials with or without laser printing (type Marresearch or Molecular Dimensions)
  • Large allowances for pin size and shape
    Length and style of the pin holding the sample may vary
  • Long term operation
    Up to 7 days autonomous operation without user intervention
    Low icing rates achieved by special anti-icing mechanisms
    Automatic liquid nitrogen refill
    Two-chambered dewar allows for smooth refill from supplying dewar during operation
  • Storage carousel for up to 19 samples
    Carousel can easily be loaded or unloaded by hand
    Automatic positioning of samples
  • High speed Phi-axis for quick centering
    Integrated automatic centering gear (x,y,z)
  • Automatic crystal finding and centering routines
    Automatic interpretation of crystal pictures captured by video camera of desktop beamline
    Semi-automatic centering option - manual intervention possible
  • Seamless integration of sample changer control into data collection software
    Sample changing is just one more parameter for data collection
    Support of mar345 image plate and marCCD detector
    Interface to automar data processing for fully automatic selection of suitable crystals
Motors
  • Carousel rotation
    Stepper motor to rotate carousel and present a vial to the vial picker
  • Vial picker
    Stepper motor to pick a vial out ot the carousel
    Stepper motor to lift the vial out of the carousel
  • Vial server
    Stepper motor to swing the vial from the vial picker to the goniometer head
    Stepper motor to translate the vial onto the goniometer head
  • Sample mounting
    Stepper motor for Phi-swing: moves goniometer head into a suitable mounting position (Chi=60 deg.)
  • Sample centering
    Stepper motor to translate the sample on the goniometer head in x-direction
    Stepper motor to translate the sample on the goniometer head in y-direction
    Stepper motor to translate the sample on the goniometer head in z-direction
  • Intelligent motor control
    All motors are driven by real-time electronics of the desktop beamline and operated in the same way as all other motors of the desktop beamline

Downloads

Download the marcsc product brochure and our movies and convince yourself how easy crystal mounting and retrieving can be using the sample changer.

Quicktime movies use the H.264 codec and therefore require Apple Quicktime ≥ 7.0.
Real Media movies use the RealVideo 10 codec and therefore require Real Media Player ≥ 10.0.
Flash movies require a Flash Player, e.g. the Adobe Flash Player.

All movies come with 320x240 pixels. resolution.

Movie Format Size (MB) Action
Sample changer Quicktime 6.2 Download
Real Media 6.1 Download
Shockwave Flash 6.0 Download
marcsc brochure pdf 0.55 Download