On-the-Fly Adjustments to Changing Fluid Properties

Dynamic Fluid Analysis technology enables Echo Liquid Handlers to adapt easily to different types of fluids. This proprietary technology enables Echo Liquid Handlers to accurately and precisely transfer most reagents, even if the Echo Liquid Handler has never previously transferred that reagent. The result of the Dynamic Fluid Analysis process is that the operator does not have to stop their work and recalibrate, ever.

Key Benefits

  • There is no need to calibrate the instrument in advance — the Echo Liquid Handler determines transfer parameters for each reagent at runtime.
  • Larger volume transfers are accomplished by transferring the same drop size repeatedly. There is no requirement to scale with volume.
  • Dynamic Fluid Analysis is an active process and therefore less sensitive to reagent changes than a single calibration point. Downstream experimental data would therefore be more consistent.
  • Dynamic Fluid Analysis determines the appropriate transfer parameters on a well-by-well basis, and therefore works with more complex reagent sets or inconsistent reagents.

By removing the calibration requirement, less time is required to maintain and operate a liquid handler. The Echo Liquid Handler uses Dynamic Fluid Analysis capabilities to simplify experimental setup and enables a higher degree of experimental and workflow flexibility.

Background on Fluid Transfer and Liquid Handlers

Fluid transfer methods are impacted by two key fluid properties: surface tension (the way fluid at an interface interacts with its surroundings) and viscosity (the resistance of fluid to move). Most liquid handlers are passive and require the operator to determine how to overcome surface tension and viscosity for their specific reagents, putting the burden on the operator to calibrate the instrument to transfer that reagent. This burden is substantial:

  • Calibrations must be verified and repeated on every instrument that is required to transfer that reagent. Calibrations usually only work over a limited volume range.
  • Calibrations may drift with the age of the liquid handler as the mechanical components wear down.
  • Calibrations are only an approximation. Calibrations against inconsistent reagents (e.g., cell lysates in a screen, or high-viscosity reagents) may not transfer accurately and precisely, which may lead to data errors downstream.
  • Calibrations cannot be developed for certain types of reagents on multichannel liquid handlers (e.g., commercially-available crystallography reagents, by design, consist of reagents of varying viscosity and surface tension properties).

Dynamic Fluid Analysis Technology Improves Liquid Handling

Echo Liquid Handlers use sound energy to transfer reagents in drop increments on a 2.5 or 25 nL scale (instrument dependent). All Echo Liquid Handlers incorporate a transducer, which converts electrical energy to sound energy to accomplish the drop transfer. The transfer process can be explained in two broad steps:


SURVEY: The Echo Liquid Handler determines the fluid height and fluid properties in the source wells. The transducer (acoustic energy generator) sends soft energy pings into each well and receives the reflections (or echoes) returned from three interfaces: the bottom of the source microplate, the bottom of the well, and the fluid meniscus.

TRANSFER: The transducer returns to the first transfer point and sends a larger energy burst to accomplish the transfer in discrete, consistent droplets.

Key to this process is that the transducer interfaces with one well at a time. This affords the capability to perfect transfer for each source well. General information on the fluid type provided by the operator (e.g., DMSO, buffer, reagent containing glycerol, etc.) narrows the transfer parameters. Dynamic Fluid Analysis uses a power-adjustment ramping process to slowly increase the energy from survey power level to transfer power levels. By listening to subsequent echoes, the Echo Liquid Handler can determine the appropriate power level required for transfer from each source well. This process is accomplished in milliseconds and does not require any operator intervention.