Troubleshooting

If you experience inaccurate dispense volumes with MANTIS, there could be a problem with the instrument’s pressure and vacuum regulators or solenoids. To check the regulator and solenoid functionality, you can use the Pneumatic System Check wizard.

Prerequisites:

• You are running MANTIS 5.1 or newer.

 

To check the pneumatic system functionality:

1. Go to the Tools menu and select Pneumatic System Check.

2. MANTIS first will check the pressure and vacuum regulators’ functionality. The check involves the pressure and vacuum testing generated by the regulators for dispensing with diaphragm chips, and the bottle pressure value used for Continuous Flow dispense.

3. After the check has completed, test results will be automatically generated in the table with the status indicator either passed or failed .

   

   Chip, Vacuum, and Bottle Values are Within the Expected Range

   

   Regulator Check Failed

4. If there is no regulator error detected, click Solenoid Check to proceed with the solenoid functionality test. Click Close to stop the test and close the wizard.

   Note: If any regulator failed or the generated values are outside of the expected range, Retry the test or click Contact Support and Continue to report the issue to the FORMULATRIX support.

5. When the Solenoid Check finished, the result will be generated in the table with the passed or failed statuses.

   

   No Solenoids Are Stuck

   

   MANTIS Detected Stuck Solenoid

   Note: If MANTIS detected a stuck solenoid or any of the generated values are outside of the expected range, click Retry to run the solenoid test or Contact Support and Continue to report the issue.

6. Click Close to finish the test and close the wizard.

For more information, see Pneumatic System Check.

Incorrect dispense volumes may occur if the chip type in use is different from the chip type selected in the MANTIS software. Check that the chip type selected in the software is correct; if not, select the correct chip type. See Input Control Panel for modifying and selecting your chip types correctly.

Check the tube connection and make sure it is firmly attached to the chip/tube input. If you see either if these issues after the first dispense or after the chip returns in between reagents, then make sure you are priming the chip before each dispense. Failure to prime a chip will prevent accurate dispenses. Please also note that it takes approximately 150-200 µL to prime the chip for the first dispense.

Sometimes the chips wear out. We recommend that you try dispensing with multiple chips. If the problem persists, contact support by emailing support@formulatrix.com. If you are on maintenance, you will be shipped a loaner MANTIS, instructed to ship yours to support for repairs, and when you receive the repaired device you must ship back the loaner.

The most common cause of this issue is a misalignment of the wash station position. To fix this problem, tune the wash station position from the Wash And Waste Station Tuning wizard. The wizard provides you with easy on-screen instructions to follow. See the Tuning Wash and Waste Station for more information.

If the problem persists, contact support@formulatrix.com for further assistance.

If your computer is showing that MANTIS USB drive is read-only, you will not be able to use the software because the software frequently writes to the USB drive. There are two ways to fix this issue. 1) Contact support by emailing support@formulatrix.com. FORMULATRIX will send you a loaner MANTIS if you are on maintenance and replace the USB drive on your MANTIS. 2) To fix this issue, copy the contents of the USB drive onto your computer, so that when you run the software you are running it locally instead of from the USB drive. Or if you are on maintenance, you can contact support by emailing support@formulatrix.com to get a replacement drive.

These problems are caused by USB communication issues. Please contact support by emailing support@formulatrix.com. If you are on maintenance, they will issue a loaner device to use while yours is repaired.

This issue can be fixed by calibrating the chip port positions.

• Make sure that you have accurately registered your plate definition in the Plate Type Library. For more information, see Adding Plate Types to the Plate Type Library.

• If the plate definition has been accurately entered but the problem persists, contact support@formulatrix.com to adjust the deck geometry setting through the Deck Geometry Correction wizard.

• If you are attempting to open or close the dispense design using a spreadsheet program such as Microsoft Excel, it can take a few moments for the software to translate your actions. Please be patient.

• Check that you are not in Summary View or Volume Error View. These two views will "freeze" the rest of the interface. Switch back to Designer View in order to enable the rest of the software's functionality. To change views, click the button at the top of the plate designer to display the alternative views.

 

The MANTIS Software Seems Frozen

Air Ribbon at the Back of the MANTIS Arms

In the case of liquid being spilled on top of the chip, the liquid can enter the MANTIS Air Ribbon when the chip is being picked up or dropped off. A ruptured chip can also cause liquid to enter the Air Ribbon, and furthermore, to the solenoid bank. This potentially will cause damage to the MANTIS instrument.

MANTIS’s Breach Detection sensor can detect this liquid breach in the Air Ribbon and will automatically display the Purging After Breach Detected window. This indicates that MANTIS is giving pressure to purge the liquid out of the Air Ribbon through the chip or MANTIS hand.

Purging After Breach Detected Window

If MANTIS detected any liquid breach in the Air Ribbon and displayed the purging window, follow these steps:

1. Wait until MANTIS finishes purging the liquid. The default purging time is 60 seconds. MANTIS software will run the following options based on the chip detection in the MANTIS software. See the image below for reference.

   • If the chip is on the MANTIS hand:

     1. The arm will move to the assigned chip changer.

     2. The hand will detach the chip.

     3. MANTIS will purge the liquid on the chip.

        

        Chip is Attached on Hand

   • If there is no chip on the hand, the MANTIS arm will move directly to the Waste Station and purge the liquid.

     

     No Chip Detected on Hand

     MANTIS Hands Purging in the Waste Station

2. OPTIONAL: If by visual estimate the liquid has been purged from the Air Ribbon before 60 seconds, click Stop to end the process. However, we do not recommend stopping the purging before the Air Ribbon is empty. Otherwise, there will be clogging in the Air Ribbon that might affect the pneumatic system.

3. Click Acknowledge to close the window after the purging.

   

   Click Acknowledge to Close the Notification

4. If you notice there are still liquid droplets in the Air Ribbon, do manual purging by following these steps:

   • Go to the Tools menu and select Purging Tool.

     

     Purging Tool Option

   • Click Start to begin the purging. The default purging time is 5 minutes.

     

     Purging Tool Window

   • Click Stop if you see the Air Ribbon is clear before the default time. If there is still liquid in the Air Ribbon, repeat steps a and b until it has all been purged.

   • Click Cancel to abort the process and/or close the window.

5. Replace the affected chip with a new one. For more optimal operation, replace the Air Ribbon to avoid any possible issues in the future. Contact support@formulatrix.com for assistance.

For more information, see MANTIS Smart Detection Sensor System.

Splashing or rebounding of drops from conical (‘V’ or ‘U’) bottom plates, such as PCR plates, may occur during dispensing with the MANTIS. This issue is most common when large volume drops land near the center of the wells, which causes either splashing onto the top of the plate or the underside of the chips.

Splashing Drops on the 96-well PCR Plate

Splashing Drops Stuck on the Underside of a MANTIS Chip

There are two primary adjustments to address this issue:

• Adjust the A1 Well Offset
• Set the Min SD Pumps

 

Adjust the A1 Well Offset

Prerequisites:

• You have powered on the MANTIS instrument and connected via the MANTIS software.
• You have at least 1 MANTIS chip installed on the chip changer. The target plate has been placed on the MANTIS deck.

 

To adjust the A1 well offset:

1. In the MANTIS software, go to the Tools menu, and select Plate Type Editor.

2. Open the plate definition of your choice by following the steps below:

   1. Click File and select Open, or press Ctrl+O on your keyboard.

      

      Select Open

   2. In the Open Microplate Definition window, select the plate that you want to edit.

   3. Click Open.

      

      Open Microplate Definition Window

3. Select a reagent from the dropdown menu to instruct the MANTIS to pick up your test chip.

   

   Selecting Reagent from the Dropdown Menu

4. Click the Move To A1 Position location buttonto move the MANTIS hand to the current A1 well location.

5. Modify the A1 well position by controlling the MANTIS hand via the Motion Control Pad. Use the arrow keys to maneuver the nozzle so it is not centered above the A1 well.

   

   Motion Control Pad

   Note: The plate preview in the Plate Type Editor window displays the expected position of the chip nozzle toward the wells. You can get a good view of the nozzle location by looking down the nozzle tip from the front of the MANTIS. For reference see the images below.

   Nozzle Centered Over Well

   Nozzle Offset to Edge of Well

6. This offset will cause the drops to catch on the walls of the wells and “roll” down to the bottom of the well. This lessens the momentum of the drop and reduces the likelihood of splashing/bouncing.

   Nozzle Centered Over Well

   Nozzle Offset to Edge of Well

7. Choose from the following options to save the adjustments:

   • If you are using a custom plate: Go to the File menu and click Save, or press Ctrl+S on your keyboard.

   • If you are modifying a default plate: Click Save As under the File menu, type a name for your plate in the Microplate Name field of the Save Plate Definition window, and click Save.

     

     Save Plate Definition Window

8. When you’re done, close the window and run a dispense to test the A1 position configuration.

9. OPTIONAL: Continue to set the Min SD Pump.

    

Set Min SD Pump

The Min SD Pumps parameter will force the MANTIS chip to use the Small Diaphragm (SD) for a minimum of ‘X’ pulses in each well prior to using the large diaphragm. This pre-fills the well with small drops so larger drops contact the pre-filled liquid, reducing the likelihood of splashing/bouncing.

Prerequisite:

• You have opened the target plate definition in the Plate Type Editor.

To set the Min SD Pumps:

1. In the Plate Type Editor window, change the Min SD Pumps value under Rectangular Plate tab to 6. You may be able to reduce this value as low as 2-3 after some testing.

Set the Min SD Pump Value to 6

2. Save the changes by selecting the Save option under the File menu, or pressing Ctrl+S on your keyboard.

3. Close the window, and run a dispense to test if the splashing still occurs. If the problem persists, adjust the A1 Well Offset. Contact FORMULATRIX support at support@formulatrix.com for further assistance.

Note: When dispensing, make sure that the Enable Min SD Pump setting is True.

Enable Min SD Pump Setting