|
|
Cell segmentation from wide-field light microscopy images using CNNs
GHAZNAVI, Ali
Image object segmentation allows localising the region of interest in the image (ROI) and separating the foreground from the background. Cell detection and segmentation are the primary and critical steps in microscopy image analysis. Analysing microscopy images allows us to extract vital information about the cells, including their morphology, size, and life cycle. On the other hand, living cell segmentation is challenging due to the complexity of these datasets. This research focused on developing Artificial Intelligence/Machine Learning methods of single- and multi-class segmentation of living cells. For this study, the Negroid cervical epithelioid carcinoma HeLa line was chosen as the oldest, immortal, and most widely used model cell line. Several time-lapse image series of living HeLa cells were captured using a high-resolved wide-field transmitted/reflected light microscope (custom-made for the Institute of Complex System, Nové Hrady, Czech Republic) to observe micro-objects and cells. Employing a telecentric objective with a high-resolution camera with a large sensor size allows us to achieve a high level of detail and sharper borders in large microscopy images. The collected time-lapse images were calibrated and denoised in the pre-processing step. The data sets collected under the transmission microscope setup were analyzed using a simple U-Net, Attention U-Net, and Residual Attention U-Net to achieve the best single-class semantic segmentation result. The data sets collected under the reflection microscope setup were analyzed using hybrid U-Net methods, including Vgg19-Unet, Inception-Unet, and ResNet34-Unet, to achieve the most precise multi-class segmentation result.
|
|
|
Simple route of caspase-3 FRET sensor synthesis using “click chemistry”
Lišková, Marcela ; Křenková, Jana ; Klepárník, Karel ; Pazdera, P. ; Foret, František
Programmed cell death or apoptosis is regulated process of cell suicide. The central role in apoptosis play cysteine proteases called caspases. Caspases recognize tetra-peptide sequences Asp-Glu-Val-Asp (DEVD) on their substrates and hydrolyze peptide bonds after aspartic acid residues. Various techniques for the determination of caspase-3 are commercially available e.g. Enzyme Linked Immuno-Sorbent Assay (ELISA), Western blotting or flow cytometric analysis. The products of the cleavage can be detected by spectrophotometry, fluorimetry, chemiluminescence (CL) or ELISA. In this work, we suggested fluorescent sensor based on easily prepared Förster Resonance Energy Transfer (FRET). We use very simple chemistry called “click”. This type of chemistry takes advantages of quickness, simplicity and cheapness. “Click chemistry” is based on usage of various functional group and cross-linkers to combine individual molecules together.
|
|
|
Analysis of tissue-bound cells: Novel approaches using laser capture microdissection
Matalová, Eva ; Adamová, Eva ; Klepárník, Karel
Recent biomedical research prefers analysis of homogenous samples obtained from primary cells to cell lines. Moreover, attention is paid to cells of low number but high biological impact, such as signalling centres in embryonic development, stem cells or tumour cells. To localize cells of interest within an organ/tissue, histological sections are widely used. However, the methods of choice for further analysis of such samples are mostly limited to histochemistry, immunohistochemistry and in situ hybridization.
|
guest ::
