Oryx8 quickly and accurately dispenses vapor diffusion drops from pre-dispensed reservoirs into sitting drop wells of all high quality vapor diffusion trays, including multi-drop plates. Protein is added at the same time using our unique multi-bore dispensing technique.

A new sliding evaporation shield provides extended protection for nanodrops and multiple drop vapor diffusion screening experiments. Microbatch experiments are automatically covered with oil within seconds of being dispensed.

Our suite of software includes packages for screening and optimization. It provides easy-to-use interfaces for setting up screening experiments and virtually effortless design of complex multivariate optimization experiments. Algorithms calculate and control pH for any number of buffer species; this provides precise control and knowledge of experiment pH.

Fast, parallel dispensing of all components of optimization experiments deliver up to 384 microbatch wells per hour, automatically covered with oil with no further requirement for sealing.

 Advantages:

• Vapor diffusion nanodrops (0.1 + 0.1µl)
   

• Microseed Matrix Screening
   

• Fast

  • Up to 384 completed wells per hour for optimization

  • 96 wells in 12 minutes for sitting drop transfer

  • 96 wells in 50 minutes for microbatch screening experiments

• Uses little protein

  • Screening experiments as small as 0.1µl +0.1µl can be dispensed reliably
     

• 7-Channel optimization
   

• Multi-component pH control
   

• Affordable
   

• Microbatch screening finds more leads
   

• Versatile - offers screening and optimization with a choice of plates and layouts.

1. Hardware

Oryx8 is driven by a PC, which is connected to a stepper motor drive box (MCC). This is connected to 8 motorized syringes (1 large and 7 small) mounted at the back of the two chassis, and to the XYZV Plate Loader, which has a moving table and two arms.

·        Small volumes are dispensed by the left-hand arm, using the seven small (100 µl) motorized syringes. 

·        Small volumes are dispensed from a two-bore or seven-bore microtip.

·        Stock solutions do not come into contact with the motorized syringes, which are filled with degassed pure water - this avoids the need for flushing out the syringes when the stock solutions are changed. 

·        The manual syringes on the front panel are used to refill the motorized syringes, to remove air bubbles, and to load stock solutions.

·        Large volumes, including oil for microbatch experiments are dispensed by the right-hand arm using the large (10 ml) motorized syringe.  A 1 ml disposable tip is used for this.

2. What it does

a. Sitting Drop Crystallization

Oryx can rapidly dispense the droplets into trays such as Crystal Clear, Cryschem, Greiner or Corning plates for sitting drop crystallization. One channel of a 2-bore microtip is loaded with protein at the start of the experiment, then, for each well, reservoir solution is picked up with the other bore and transferred to the droplet.  Protein is dispensed at the same time as the reservoir solution and mixed by stirring.

Multi-drop plates can be dispensed to with differing proportions of protein or up to three different protein variants. A sliding evaporation shield covers and protects the drops during the time that it takes to dispense the experiment

b. Microbatch screening

Oryx8 is used for screening (finding new crystallization conditions) using the microbatch crystallization method.  Here droplets are dispensed into plastic plates and covered with oil to prevent evaporation.  We generally dispense 0.2 to 2 µl into the bottom of each well.  In order to dispense these very small droplets accurately, a special proprietary microtip is used.

Oryx has an extra liquid handling channel that can be used to cover microbatch droplets with oil immediately after dispensing.  This prevents the microtip from coming into contact with the oil, which would significantly reduce accuracy.  (This is the reason that Oryx is more accurate than IMPAX for dispensing microbatch experiments.)

Typically 96 premixed solutions can be combined with protein for screening. These solutions are placed on the right-hand side of the Plate Loader.  A two-channel microtip is used to mix the solutions with protein. One channel is loaded with the correct amount of protein at the start of the experiment. The other channel is used to pick up 0.1 to 1 µl of the first screening solution and transfer it to the first well of the VB plate. It is dispensed and mixed with 0.1 to 1 µl of protein from the other channel. Oil is immediately dispensed by the second arm to cover and protect the drop. The microtip is then rinsed. This is repeated for all 96 solutions. It takes about 5 minutes for the user to set up a screening experiment, and 50 minutes to dispense a screen with 96 solutions.

c. Microbatch optimization

A sophisticated “spreadsheet” environment is provided for designing and carrying out optimization experiments.  The stock solutions are shown on the left.  Each cell represents one well.  The user can input concentrations simply by double-clicking on a well. 

By defining the wells at opposite corners of a block, and selecting “interpolate”, the user can rapidly define 2D grids.  A similar routine automatically generates a multi-dimensional multivariate experimental design.  Here the conditions are based on the conditions in a single well – the user chooses the total amount of variation that he would like for each variable as a percentage.  See our research report “Practical Experimental Design Techniques” for more details.

The branches of the 7-channel microtip act as reservoirs for protein, precipitant, pH buffer solutions and additives. These are loaded using the lower row of valves and the disposable syringes. Solutions are dispensed using the motorized gas-tight syringes, which contain water.

Exactly the right amount of protein is loaded by sucking it into one bore of the microtip. It is kept separate from the water already in the bore by a small air bubble. Solutions are dispensed from all bores simultaneously. 96 wells can be dispensed in around 15 minutes. As with screening, oil is dispensed by Oryx onto each droplet immediately after it is dispensed.