Abstract
- •Problem: Media exchange for 3D spheroid culture is a major automation bottleneck due to tissue loss with conventional aspiration and limited scalability.
- •Solution: Automated workflow for 384- and 96-well U-bottom plates using optimized nozzle geometry and low-shear fluidics.
- •Result: Zero tissue loss after five wash cycles; 80% volume exchange; 20 plates processed hands-off in 1–1.5 hours.
Approach
- •Custom washing cassettes on INTEGRA WELLJET with eight nozzles and passive valving.
- •Gentle aspiration of used medium; fresh medium dispensed through bent steel nozzles against well wall to minimize flow across spheroids.
- •Cell Culture: MCF7 in DMEM (+10% FBS, 1% Pen/Strep); Akita PrimeSurface 384 and Thermo Nunclon Sphera 96 U-bottom plates; 5 cells/µL; 70 µL (384) / 200 µL (96) dispensed volumes.
Results
- •80% volume exchange (55 µL aspirated from 70 µL in 384; 145 µL from 200 µL in 96).
- •Zero tissue loss confirmed by microscopy after five wash cycles.
- •Processing: < 2.5 min (96-well), < 5 min (384-well).
- •> 20 plates can be stacked and processed without operator intervention.
- •Washing tested for Matrigel domes in flat-bottom wells; HTS-compatible.
Joint system for media exchange comprising:
INTEGRA WELLJET and ADDIMUS washing cassette
Fig. 1: Integra's WELLJET Dispenser Stacker
Fig. 2: ADDIMUS's WASH+ cassette incl. passive valving
Wash Principle and Sample Results
Fig. 3: Schematic of washing
Fig. 4: (Left) 96-well-plate before exchange of medium;
(Right) 96-well-plate after exchange of medium
See the workflow in action
View Demonstration