Abstract
- •Matrigel is an essential reagent in 3D cell culture and needs to be handled below 10 C to prevent gelation.
- •Off-the-shelf bulk dispensers such as the MultiDrop Combi do not support cooled dispensing.
- •Conventionally, researchers pre-cool the dispensing cassette with ice-cold PBS, but this still results in dispensed sample temperatures above 15 C.
- •We present a simple cooling solution for bulk dispensers that cools the sample below 10 C and enables filling more than 10 plates.
Approach
- •10x reduced dead volume, down to about 100 µL, through a novel dispensing cassette design.
- •Passive pump cooling with phase change material and a custom designed aluminum casing.
- •Passive reservoir cooling with phase change material.
- •Single-use reservoirs mountable directly on the cassette for a compact cooled dispensing workflow.
Results
- •Cooled sample can be dispensed below 10 C for more than 10 384-well plates.
- •4 µL domes can be robustly placed in 96-well plates.
- •7 µL is sufficient to cover the bottoms of 384-well plates.
- •Cell viability has been confirmed by culturing MCF7 breast cancer cells after dispensing.
Cooling setup and elongated nozzle geometry
Fig. 1: Passive pump cooler and reservoir cooler mounted on dispenser
Fig. 2: Elongated dispensing nozzles allow accurate dome placement
Reservoir and cassette architecture for cooled low-volume dispensing
Fig. 3: a) Different reservoir and cooler sizes; b) low dead volume cassette with elongated dispensing needles
Dome placement and thermal performance during dispensing
Fig. 4: a) Matrigel dispensed in 384-well plate; b) 4 µL Matrigel domes in 96-well plate; c) temperature of the dispensed liquid with or without cooler
Cell culture compatibility and confluency after dispensing
Fig. 5: Cell culture images and confluency over time
