Dispense to Waste (Bravo)

Description

The Dispense to Waste (Bravo) () task moves the pipettes by a horizontal offset and then dispenses used fluid in between the chimneys in the Tip Wash Station. The software calculates the horizontal offset automatically based on the labware definition for the Tip Wash Station.

 

Task is available for...	Task is available in...
Tip Wash Station (MicroWash Reservoir) on Bravo Platform	Main Protocol, Bravo Subprocess

Task parameters

After adding the Dispense to Waste task at the desired point in the protocol, set the following parameters in the Task Parameters area:

 

 

 

 

Parameter	Description
Location, plate	The Tip Wash Station involved in the Dispense to Waste task. Note: The Tip Wash Station is also known as the Microwash Reservoir.
Location, location	The location of the Tip Wash Station at which the Dispense to Waste task occurs. <auto-select> If accessories are installed on the deck, the software uses the accessory configuration information in Bravo Diagnostics to determine the correct location for the task.
Empty tips	The option to empty all the liquid from the head into the Tip Wash Station outside the chimneys.
Volume (µL)	The volume of liquid to be dispensed from each pipette.
Blowout volume (µL)	Specifies the volume of air to dispense after the main volume has been dispensed while the tips are still in the Tip Wash Station.
Liquid class	The pipetting speed and accuracy. IMPORTANT To ensure consistent pipetting, always select a liquid class for liquid-handling tasks.
Override dispense flow rate from liquid class	The option to override the dispense velocity specified in the liquid class. Selecting this option enables you to specify a value for the dispense flow rate without changing the liquid class.
Dispense flow rate (0–500 µL/s)	The numerical value or the JavaScript variable that will override the dispense velocity setting in the liquid class. A JavaScript variable enables the value to be assigned later, for example through a VWorks form. Using a VWorks form, an operator could easily change the flow rate for a dispense step in increments from as low as 1 µL/min up to 1001 µL/min using the same liquid class. If the task is included in a VWorks macro, a JavaScript variable enables you to change the value for the task at the macro level. IMPORTANT The software requires that the flow rate value be in microliters per second (µL/s) at run time. If you want an operator to enter the value in microliters per minute (µL/min), you can use scripting to convert the values for the software to use.
Distance from well bottom (mm)	The absolute distance between the end of the pipette tips and the bottom of the Tip Wash Station during the Dispense to Waste task. If you specify dynamic tip retraction, this is the starting distance. IMPORTANT The labware definition must be accurate and the teachpoint must be precise in order for the system to position the tips at the correct distance from the well bottom.
Dynamic tip retraction (mm/µL)	The rate at which to raise the pipette head during the Dispense to Waste task. Use dynamic tip retraction to prevent spills as the pipette tips displace the liquid. To move the pipettes: • At the same rate as the volume change. Calculate dynamic tip retraction (DTR) as follows: DTR = (well depth)/(well vol) = 1/A, where A is the cross-sectional area of a well with straight walls • Faster than the volume change. DTR > 1/A • Slower than the volume change. DTR < 1/A The starting and ending positions can be calculated as follows: (Vdispensed * DTR) + Distancewell bottom
Well selection	The chimney locations at which the Dispense to Waste task occurs. Click in the parameter box, and then click the Browse button to select the locations in the Well Selection dialog box. Use this parameter only if the pipette head has fewer tips or cartridges than the number of locations in the wash station, or if you are in single-row or single-column mode.
Perform tip touch on North/East side	The option to touch the tip on an outer side of the adjacent northeast chimney or wall in the Tip Wash Station after performing the dispense.
Tip touch retract distance (–20 to 50 mm)	The vertical distance for the pipette tips to rise before performing the tip touch.
Tip touch horizontal offset (–5 to 5 mm)	The horizontal distance the tips move. The value is based on the well diameter specified by the labware definition. For example, if you set a value of: • 0, the tips move a horizontal distance equal to the well radius • > 0, the tips attempt to move past the well radius, which results in a more forceful tip touch • < 0, the tips move a distance less than the radius of the well, resulting in a lighter tip touch

 

 

Example: Dispense into a Tip Wash Station on the Bravo Platform using a Bravo 96AM Head

Goal

After aspirating fluids up through mounted AssayMAP Bravo cartridges, remove the cartridges, dispense the contents of the Bravo 96AM Head syringes at a Tip Wash Station, remount the cartridges for additional aspiration steps.

Implementation

In Bravo Diagnostics, set up the Tip Wash Station on a deck location. Associate the station with one or more pump modules.

In the protocol, add a configured labware for the Tip Wash Station in addition to the other processes and configured labware required by the protocol. In the example shown, the configured reservoir is called Wash.

In the Bravo subprocess where the liquid-handling tasks are specified, a Dispense to Waste task is added after a series of aspiration tasks.

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In the Dispense to Waste Task Parameters area, the Tip Wash Station is selected so that the task is performed in this labware.

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Related information

 

For information about...	See...
Adding devices	• Adding devices • Device user guide
Adding tasks in a protocol	Adding and deleting tasks
Liquid classes	VWorks Automation Control Setup Guide
Pipette techniques	Specifying pipetting techniques
Aspirate task	Aspirate (Bravo, Vertical Pipetting Station)
Set Head mode task	Set Head Mode (Bravo)
Tips On task	Tips On (Bravo, Vertical Pipetting Station)
Tips Off task	Tips Off (Bravo, Vertical Pipetting Station)
Microplate-handling tasks	Setting parameters for microplate-handling tasks
Microplate-storage tasks	Setting parameters for microplate storage tasks
I/O-handling tasks	Setting parameters for I/O-handling tasks
Scheduling tasks	Setting parameters for scheduling tasks