How to use the Dragonfly
The Dragonfly liquid handler uses positive displacement pipetting with disposable tips to set up custom crystallisation screens from stock solutions. Running an experiment on Dragonfly takes between 5 and 15 minutes depending on the complexity of the custom screen so there is no booking system for Dragonfly. Consumables for Dragonfly (tips, inserts, reservoirs, etc) are included in the cost of an empty crystallisation plate.
Before the experiment
Local rules
As Dragonfly formulates crystallisation screens from user-defined stock solutions to make precipitant and pH gradients for optimising crystal hits. Depending on the nature of the chemicals to be used please follow the following rules as required.
- The use of cacodylate-based buffer solutions is strictly prohibited. MES provides a similar pH range as a substitute.
- Please use PPE (gloves, labcoat etc) when handling chemical solutions.
- Any stock solution presenting an inhalation hazard need to be cleared by the facility manager before use on Dragonfly.
- Please bring minimal amounts of stock solutions to the laboratory for Dragonfly use (50 ml). If you need to use more than 50ml of stock solutions (excluding water) please let the facility manager beforehand.
- Please retrieve all stock solutions when finished. Excess stock solutions in Dragonfly reservoirs should be poured back into your tubes.
- It is the user’s responsibility to deal with spillages and keep the area around Dragonfly clean and safe for the next user.
You can design your optimisation screen using the DFDesigner software. DFDesigner software is freely available to all users with a Windows computer and is very easy to use. Sam Horrell can be contacted with any questions you have on screen design.
When designing your screen consider your stock concetrations carefully, too high a concetration can mean the dragonfly can't accurately pipette the small volumes and too low a concetration might mean too much volume is required to fit all components into the 85 ul well.
The disposable tips have a maximum fill volume of 4 ml, if this is exceeded for one or more components a warning will alert you to this. If this is the case you can select the “split between tips” option to dispense stock solution from 2 (or more) tips the the software that runs the Dragonfly (Not the designer).
Dragonfly DFDesigner tutorial video
Dragonfly accepts a number of different plates for performing your optimisations in:
- MRC 2-well
- SwissCi SD-3
- Greiner CrystalQuick triple well
- Greiner CrystalQuick X
- Greiner 96
- Corning CrystalEX
- Corning CrystalEX second generation
- TTP IQ
- TTP 96
- Robbins Intelliplate
- Qiagen (Nextal) EasyXtal 15
- Axygen 1ml 96 deep well
- VDX48
- MRC Maxi
- Corning 96
Please note that VDX24 well and Linbro 24 well plates cannot be used on Dragonfly.
Export your screen for use on Dragonfly.
Ensure you have selected the correct format of wells (rows by columns) and well volume in DFDesigner before exporting your screen. Export your optimisation screen as a csv file (save in the optimisations folder), and also as a DFY settings file. There is also an option to export as a pdf for a comprehensive record of your screen.
Running your experiment
Running an experiment on Dragonfly tutorial
Turn on the instrument and wait 15 seconds before launching the Dragonfly software on the laptop. Otherwise the software will run in simulation mode. Import your csv into the Dragonfly software and ensure the correct plate and well number have been selected. Move to the setup tab in the Dragonfly Software and prepare the the disposable tips (with insert) according to the diagram. If the tip has been properly loaded a little green box appears on screen for that location.
Next load your reservoirs into the Dragonfly tray and add your stock solutions to the reservoirs. The reservoirs have 2 lines indicating 5 and 10 ml fill volumes. The minimum volume allowed in a reservoir is 0.5ml. Load your chosen plate type into the Dragonfly plate holder.
Select Aspirate and the Dragonfly will prime the inserts and then aspirate the stock solutions. After aspirating the Dragonfly will eject some solution to remove any air bubbles. You are now ready to hit Run and your screen will begin dispensing.
After your experiment
DO NOT TRY TO REMOVE THE DISPOSABLE TIPS BEFORE HITTING THE “REMOVE” BUTTON. THERE WILL BE A METAL PLUNGER IN THE WAY.
“Remove” purges the excess solution in the tips back into the reservoirs and then takes the rods out of the tips for safe removal. If the rods are still in the tips then you risk damaging the instrument when taking out the tips.
To dispose of unwanted stock solutions please do not pour them down the sink. Excess stock solutions should be poured back into their original container and disposed of at user’s leisure in their laboratory space. Please clear up any spillages and dispose of any unwanted Dragonfly consumables in the orange bin provided.
I reccomend keeping yout stock solutions sealed with parafilm to be reused if crystallisation is successful.
