A simple automatic liquid dispense arrangement (SALDA) for timelapse microscopy

Zenodo hosts the archival version of this document; for convenient viewing, please visit https://amsikking.github.io/SALDA_for_timelapse_microscopy Abstract A recurring challenge in timelapse microscopy is adding a liquid perturbation to a sample during imaging and observing the response (e.g. adding a drug). This is typically done by a person hovering over the microscope with a pipette and trying to gently add liquid in a precise location. This method is hard to execute and time accurately, upsets environmental control (e.g. temperature and CO2) and often results in vibrations that disturb or destroy the imaging. Here we present a simple automatic liquid dispense arrangement (SALDA) for timelapse microscopy that is readily deployed and cost effective. We use a programmatically controlled syringe pump with a refined fluidic and mechanical arrangement to dispense liquid directly into multiwell samples that are being imaged by a microscope. The arrangement enables accurate and repeatable timing, eliminates environmental disturbance and vibrations from the user, and facilitates perturbing and imaging of different wells. The fluidic system is readily cleaned or replaced and can dispense volumes as low as 10µl with high trueness (RB = 0.32%) and precision (CV = 1.63%). Here we show the arrangement with a particular stage top incubator and microscope platform, but the setup is easily modified and applied to any system that can accommodate a small diameter tube (~2 mm).