LIFTOSCOPE: development of an automated AI-based module for time-effective and contactless analysis and isolation of cells in microtiter plates.

BACKGROUND: The cultivation, analysis, and isolation of single cells or cell cultures are fundamental to modern biological and medical processes. The novel LIFTOSCOPE technology aims to integrate analysis and isolation into one versatile, fully automated device. METHODS: LIFTOSCOPE's three core technologies are high-speed microscopy for rapid full-surface imaging of cell culture vessels, AI-based semantic segmentation of microscope images for localization and evaluation of cells, and laser-induced forward transfer (LIFT) for contact-free isolation of cells and cell clusters. LIFT transfers cells from a standard microtiter plate (MTP) across an air gap to a receiver plate, from where they can be further cultivated. The LIFT laser is integrated into the optical path of an inverse microscope, allowing to switch quickly between microscopic observation and cell transfer. RESULTS: Tests of the individual process steps prove the feasibility of the concept. A prototype setup shows the compatibility of the microscope stage with the LIFT laser. A specifically designed MTP adapter to hold a receiver plate has been designed and successfully used for material transfers. A suitable AI algorithm has been found for cell selection. CONCLUSION: LIFTOSCOPE speeds up cell cultivation and analysis with a target process time of 10 minutes, which can be achieved if the cell transfer is sped up using a more efficient path-finding algorithm. Some challenges remain, like finding a suitable cell transfer medium. SIGNIFICANCE: The LIFTOSCOPE system can be used to extend existing cell cultivation systems and microscopes for fully automated biotechnological applications.

Interferometric Imaging of Solvent Vapor of Evaporating Liquid Films.

The liquid deposition of thin films requires a thorough understanding of the underlying drying process, as it is an essential subprocess, where many defects may arise. To complement experimental studies, the present study uses a laser Michelson interferometer to visualize the vapor cloud of evaporating liquid films. The recorded interferometric patterns are evaluated using windowed Fourier filtering and a novel phase-unwrapping algorithm to allow for a robust analysis. Thin solvent stripes of different lengths are combined to yield a quantitative two-dimensional distribution of the solvent vapor concentration along a thin liquid stripe. The results show a considerable influence of natural convection during evaporation.