Deep learning enabled label-free microfluidic droplet classification for single cell functional assays

Front Bioeng Biotechnol. 2024 Sep 18:12:1468738. doi: 10.3389/fbioe.2024.1468738. eCollection 2024.

Abstract

Droplet-based microfluidics techniques coupled to microscopy allow for the characterization of cells at the single-cell scale. However, such techniques generate substantial amounts of data and microscopy images that must be analyzed. Droplets on these images usually need to be classified depending on the number of cells they contain. This verification, when visually carried out by the experimenter image-per-image, is time-consuming and impractical for analysis of many assays or when an assay yields many putative droplets of interest. Machine learning models have already been developed to classify cell-containing droplets within microscopy images, but not in the context of assays in which non-cellular structures are present inside the droplet in addition to cells. Here we develop a deep learning model using the neural network ResNet-50 that can be applied to functional droplet-based microfluidic assays to classify droplets according to the number of cells they contain with >90% accuracy in a very short time. This model performs high accuracy classification of droplets containing both cells with non-cellular structures and cells alone and can accommodate several different cell types, for generalization to a broader array of droplet-based microfluidics applications.

Keywords: Resnet 50; convolutional neural network; deep learning; droplet-based microfluidic; image classification; image preprocessing.

Grants and funding

The authors declare that financial support was received for the research, authorship, and/or publication of this article. MB is the recipient of a CIFRE PhD fellowship in collaboration with Evextabio, Paris, France. TV is the recipient of a PhD fellowship from École polytechnique, Palaiseau, France (AMX fellowship 2023–2026). LZ is the recipient of a fellowship from the French Ministère de l’Enseignement Supérieur et de la Recherche (MESER). PB acknowledges funding from the Agence Nationale de la Recherche (ANR) ANR-21-CE15-0027-01 project CURAREP, from Fondation pour la Recherche Médicale Programme « Espoirs de la Recherche » Equipe FRM 2022 (EQU202203014631), from the Institut Carnot Pasteur Microbes et Santé, from the CAPNET (Comité ad-hoc de pilotage national des essais thérapeutiques et autres recherches, French government) MEMO-VOC, from the Institut Pasteur and from the Institut National de la Santé et de la Recherche Médicale (INSERM).