No abstract

The advent of single‐cell methods is paving the way for an in‐depth understanding of the cell cycle with unprecedented detail. Due to its ramifications in nearly all biological processes, the evaluation of cell cycle progression is critical for an exhaustive cellular characterization. Here, we present DeepCycle, a deep learning method for estimating a cell cycle trajectory from unsegmented single‐cell microscopy images, relying exclusively on the brightfield and nuclei‐specific fluorescent signals. DeepCycle was evaluated on 2.6 million single‐cell microscopy images of MDCKII cells with the fluorescent FUCCI2 system. DeepCycle provided a latent representation of cell images revealing a continuous and closed trajectory of the cell cycle. Further, we validated the DeepCycle trajectories by showing its nearly perfect correlation with real time measured from live‐cell imaging of cells undergoing an entire cell cycle. This is the first model able to resolve the closed cell cycle trajectory, including cell division, solely based on unsegmented microscopy data from adherent cell cultures.

Bisphenol-A, a synthetic organic compound with estrogen mimicking properties, may enter bloodstream through either dermal contact or ingestion. Probiotic bacterial uptake of bisphenol can play a major protective role against its adverse health effects. In this paper, a method for the quantification of BPA in bacterial cells of L. lactis and of BPA and its potential metabolites 4-hydroxybenzoic Acid, 4-hydroxyacetophenone and hydroquinone in the culture medium is described. Extraction of BPA from the cells was performed using methanol-H 2 O/TFA (0.08%) (5:1 v/v) followed by SPE. Culture medium was centrifuged and filtered through a 0.45 µm syringe filter. Analysis was conducted in a Nucleosil column, using a gradient of A (95:5 v/v H 2 O: ACN) and B (5:95 v/v H 2 O: ACN, containing TFA, pH 2), with a flow rate of 0.5 mL/min. Calibration curves (0.5-600 µg/mL) were constructed using 4-n-Octylphenol as internal standard (1 > R 2 > 0.994). Limit of Detection (LOD) and Limit of Quantification (LOQ) values ranged between 0.23 to 4.99 µg/mL and 0.69 to 15.1 µg/mL respectively. A 24 h administration experiment revealed a decline in BPA concentration in the culture media up to 90.27% while the BPA photodegradation levels were low. Our results demonstrate that uptake and possible metabolism of BPA in L. lactis cells facilitates its removal.