Aspirate task parameters About this topic The Aspirate task draws liquid from a microplate or reservoir. This topic describes the task parameters. To run the Aspirate task, see Performing a task using Bravo Diagnostics. Parameter description The Aspirate task has the following parameters. Parameter Description Volume (µL) The volume of liquid to be drawn into each pipette tip. Pre-aspirate volume (µL) The volume of air to be drawn before the pipette tips enter the liquid. Post-aspirate volume (µL) The volume of air to be drawn after the liquid is drawn. Liquid class The pipetting speed and accuracy. IMPORTANT To ensure consistent pipetting, always select a liquid class for liquid-handling tasks. Distance from well bottom(0–100 mm) The distance between the end of the pipette tips and the well bottoms during the Aspirate task. If you specify dynamic tip extension, this is the distance at the end of the Aspirate task. 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 extension (0–20 mm/µL) The rate at which the pipette head moves during the Aspirate task. The software calculates the distance over which the tips will move without crashing. Use dynamic tip extension to prevent spills as the pipette tips displace the liquid. To move the tips: • At the same rate as the volume change. Calculate dynamic tip extension (DTE) as follows: DTE = (well depth)/(well vol) = 1/A, where A is the cross-sectional area of a well with straight walls • Faster than the volume change. DTE > 1/A • Slower than the volume change. DTE < 1/A The starting and ending positions can be calculated as follows: (Vaspirated * DTE) + Distancewell bottom Note: Instead of a negative aspirated volume, the software automatically moves downward toward the well bottom with each aspirate action. Pipette technique The pipette location offset you want to use for the Aspirate task. The list of pipette techniques are defined in the Pipette Technique Editor. Perform tip touch The option to touch the pipette tip on one or more sides of the well. Which sides to use for tip touch The side or sides of the well to use during tip touch: North, South, East, West, North/South, West/East, West/East/South/North. Tip touch retract distance(–20 to 50 mm) The vertical distance for the pipette tips to rise before touching the sides of the wells. 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 Related information For information about… See… Opening Diagnostics Opening Bravo Diagnostics Editing the labware classes, liquid library, or pipetting techniques VWorks Automation Control Setup Guide Performing a diagnostic task Performing a task using Bravo Diagnostics Reporting a problem Reporting problems
