The dispense pattern here should be vertical and consistent. Issues seen here in dispensing will only become worse when working with sample later in the workflow. It is therefore critical to deal with dispensing issues before continuing to loading the sample. If 'Dispenser tested ok' is already showing, you may not need to test further.
Either press Automatic Test or Dispense to run the automatic dispenser testing or to manually test the dispenser, respectively. The Automatic Test will only report that 'Dispenser tested ok' if it achieved a high degree of consistency and verticality. If Automatic Test is pressed, the lower image, overlay legend, and results in a pink box will appear. To assess the consistency of the dispense manually, click Dispense 3-5 times in a row. You may find that you can achieve sufficiently good results for your samples by applying your own standards of consistency and verticality in manual testing.
Review how the dispenser performs in the image. If the fluid stream appears to be deflected left or right, or is out of focus, there may be small amounts of debris near the dispenser tip. The goal is to have a reproducible pattern of droplets that do not move away from vertical. Generally, when testing with water, the dispense pattern should look similar from one session to the next.
If necessary, use the Troubleshooting tab to diagnose and address issues with the dispenser.
- Inspect Dispenser moves the tip of the dispenser into the field of view of the camera and captures an image. This can be useful for visualizing bubbles, debris, or spots in the tip of the dispenser.
- Wipe Dispenser and Multi-Wipe Dispenser can be used to remove debris or liquid from the outside of the dispenser tip.
- Dip Dispenser can be used to break films which have formed, or to fill in air gaps at the tip of the dispenser. This can be used to restore dispensing capability. However, these are more likely to be useful with sample than here with water.
If the issues cannot be addressed, press Repeat Setup to return to the dispenser setup step or the Reset System button on the top toolbar to reset the system and choose the Dispenser Cleaning workflow. Generally, if extensive troubleshooting is necessary to get a dispenser to dispense with water, the best route forward is to clean the dispenser before proceeding to sample.
In the Advanced tab, there is an additional option for adjusting the Amplitude. Generally, you should not need to adjust this when dispensing water. If it is necessary to produce an adequate dispense pattern, further dispenser cleaning is likely needed.
The Remove Debris option is available if a large piece of debris is found inside of the dispenser. In this situation, it is generally not possible to push the debris out through the tip of the dispenser, and instead the strategy of pulling it up through the tubing and into the waste should be pursued. This is done using an extra-thorough backflush alternating between chamclean and air.
Once the debris has been removed, the dispenser will need to be primed again. This should be done by selecting the Troubleshooting tab, then selecting the Repeat Setup option. Inspecting the dispenser after performing a Remove Debris action will show an empty dispenser and testing the dispenser at this point will not produce droplets. It must be set-up again before these actions can be performed. If pressing Continue at this point, the doors will unlock, you will need to load more methanol and then press Setup.
Once dispensing is satisfactory, press Continue. This will trigger tweezer cleaning in ethanol and drying.