Fluid Transfer; Positioning The Ade Elements; Creating The Acoustic Pulse - Labcyte Echo 520 User Manual

A.4

Fluid transfer

Afterthe fluid survey, the Echo software uses dynamic, real-time
measurements to check the fluidlevel again and adjust the focus and power
as necessary to compensate for any changes immediately before droplets
are transferred from each well.
A.4.1 Positioning the ADE elements
Before a droplet can be ejected, the source plate gripper stage and the
acoustic transducer stage are moved on their X- and Y-axes, so that the
transducer is centered directly below the source microplate well from which
fluid will be ejected. The appropriate destination microplate well is
positioned directly above the acoustic transducer and source microplate
well.
The acoustic transducer assembly includes a fixed focal length lens. In
Figure A.1 below, two adjacent wells with different fluid fill heights are
shown. Before a droplet can be ejected, the acoustic transducer must be
positioned vertically on its Z-axis to correctly focus the acoustic energy near
the fluid's meniscus.
Figure A.1 Fixed focal length dictates Z-axis adjustment
A.4.2 Creating the acoustic pulse
The acoustic pulse frequency, amplitude, and duration are calculated
depending on the fluid volume to be transferred, the composition of the
fluid, individual acoustic transducer performance, and other factors.
The Echo liquid handler builds up larger volume transfers by ejecting
multiple 2.5 nL droplets. The multi-droplet ejection from a single well will
vary depending on the fluid composition and well fluid thickness (height).
A-4 Echo Liquid Handler User Manual