Traditional animal models to quantify the degree of blood vessel formation are being replaced by cell culture assays
that are easier to set up, statistically reliable and can be automated in a drug screening laboratory. These assays rely on the endothelial cells’ ability to form distinct blood-vessel-like tubules in an extracellular matrix where they can subsequently be visualized by fluorescence microscopy. - [Read An Image-Based Assay of Endothelial Cell Tube Formation as a Model of Angiogenesis]
Anatomy of a comparative gene expression study. Includes: Choosing Cell Populations; mRNA Extraction and Reverse Transcription; Fluorescent Labeling of cDNA's; Hybridization to a DNA Microarray; Scanning the Hybridized Array; Interpreting the Scanned Image. - [Read Anatomy of a Comparative Gene Expression Study]
Information on anatomy of a comparative gene expression study. Includes: Choosing cell populations; mRNA Extraction and Reverse Transcription; Fluorescent labeling of cDNA's; Hybridization of DNA microarray; Scanning the hybridized array; Interpreting the scanned image. - [Read Anatomy of a Comparative Gene Expression Study]
Basic information on confocal microscopy, includes: Specimen Preparation and Imaging; Objective Lens Parameters and Optical Section Thickness; The Objective Lens; Probes for Confocal Imaging; Autofluorescence; Collecting Images; Troubleshooting; Image Processing and Publication; - [Read Confocal Microscopy: Speciman Preparation and Imaging]
When imaging specimens in the optical microscope, differences in intensity and/or color create image contrast, which allows individual features and details of the specimen to become visible. Contrast is defined as the difference in light intensity between the image and the adjacent background relative to the overall background intensity. In general, a minimum contrast value of 0.02 (2 percent) is needed by the human eye to distinguish differences between the image and its background. - [Read Contrast in Optical Microscopy]
The visibility of the faint star light is enormously enhanced against a dark background. This principle is applied in darkfield (also called darkground) microscopy, a simple and popular method for making unstained transparent specimens clearly visible. Such objects often have refractive indices very close in value to that of their surroundings and are difficult to image in conventional brightfield microscopy. - [Read Darkfield Illumination]
Flow assays offer visualization of cell adhesion under wall shear stress. Visualization of the different events of cell adhesion can be quantified by selective image acquisition and subsequent image processing. Flow assays are suited for adhesive events which occur very rapidly in a time scale shorter than that of most static adhesion assays. Also, events subsequent to the initial events can be studied such as cell stabilization and spreading giving some insight into the kinetics of cell-cell. - [Read Dynamic Flow Assay for Cell Adhesion in a Parallel Plate Flow Chamber]
Flow assays allow visualization of cell adhesion under well-defined wall shear stress. Visualization of the events of cell adhesion are quantified by selective image acquisition and image processing. Events subsequent to the initial events can be studied such as cell stabilization and spreading. John T. Patton~GlycoTech Corporation, Rockville, Maryland - [Read Dynamic Flow Assay in a Parallel Plate Flow Chamber]
Most biological specimens are relatively transparent, so details of internal and intracellular morphology are difficult to image in untreated living specimens using simple bright-field techniques. Fluorescence microscopy offers greater advantages and possibilities for increasing contrast and determining the specific localization of molecules in cells. Article outlines the three methods most commonly used to introduce an appropriate label into Drosophila tissue without perturbing the process. - [Read Fluorescent Reagents for Live Cell Imaging and Their Introduction into Cells]
Protocol describes an assay that relies on the endothelial cells’ ability to form distinct blood-vessel-like tubules in an extracellular matrix where they can subsequently be visualized by fluorescence microscopy. Although quantification of the tubules can be performed by manual tracing, this method precludes the use of the assay in unbiased high-throughput applications. - [Read Image Based Assay of Endothelial Cell Tube Formation Protocol]
ImageJ - Image Processing and Analysis in Java. Useful program for MacOs MacosX and PC. Analysis includes: Measure area, mean, standard deviation, min and max of selection or entire image. Measure lengths and angles. Use real world measurement units s - [Read ImageJ - Image Processing and Analysis in Java]
In recent years, the increased sensitivity of electron detectors and the availability of low-vacuum or variable-pressure systems have allowed imaging of fresh tissue samples without the need for fixation, drying, and coating. This obviously saves a lot of time, although the image quality may not be as good as that obtained from fixed samples. However, for most applications that tend to be at a relatively low magnification, the quality can be as good as that obtained from fixed samples. - [Read Imaging of Fresh Arabidopsis Tissues in the Scanning Electron Microscope]
In recent years, the increased sensitivity of electron detectors and the availability of low-vacuum or variable-pressure systems have allowed imaging of fresh tissue samples without the need for fixation, drying, and coating. This obviously saves a lot of time, although the image quality may not be as good as that obtained from fixed samples. However, for most applications that tend to be at a relatively low magnification, the quality can be as good as that obtained from fixed samples. - [Read Imaging of Fresh Arabidopsis Tissues in the Scanning Electron Microscope Protocol]
Protocol describes the acquisition and processing of confocal
fluorescent and bright field images of live cells expressing yellow fluorescent protein (YFP), with a spinning disk confocal head on a Zeiss Axiovert 200 M microscope when three planes along the z-axis of the cell are acquired. Protocol includes: Description of Microscope and Imaging Setup; Description of Acquisition Parameters; Image Processing. - [Read Live Cell Spinning Disk Confocal Fluorescence Imaging of Cells- YFP & Bright Field—Three Z Axis]
Protocol describes the acquisition and processing of confocal
fluorescent and bright field images of live cells expressing yellow fluorescent protein (YFP), with a spinning disk confocal head on a Zeiss Axiovert 200 M microscope. Protocol includes: Description of Microscope and Imaging Setup; Description of Acquisition Parameters; Image Processing. - [Read Live Cell Spinning Disk Confocal Fluorescence Imaging of Cells- YFP and Bright Field Images]
To image early cleavages and chromatin dynamics, it is convenient to use histone H2B fused to GFP or lamin::GFP. Time-lapse movies can be obtained using conventional confocal microscope systems and their included software. Early embryos dissected from transgenic hermaphrodites are placed with egg salts on agar pads. - [Read Live Imaging of Caenorhabditis elegans: Examples]
Diffraction-limited optical microscopy requires that the spatial resolution of an image is limited by the wavelength of the incident light & by the numerical apertures of the condenser & objective lens systems.The development of near-field scanning optical microscopy (scanning near-field optical microscopy) has allowed for a imaging technique that retains the various contrast mechanisms afforded by optical microscopy methods while attaining spatial resolution beyond the optical diffraction limit - [Read Near-Field Scanning Optical Microscopy]
NIH Image. Image can be used to measure area, mean, centroid, perimeter, etc. of user defined regions of interest. It also performs automated particle analysis and provides tools for measuring path lengths and angles. Spatial calibration is supported to p - [Read NIH Image for Mac]
Protocol specifically describes data acquisition for a particular variant of GFP (EGFP) or Oregon Green as a donor fluorophore, but it can be adapted for image acquisition of other chromophore. - [Read Probing Protein Interactions Using GFP and FRET]
Paraffin Embedding Protocol for molecular profiling. This Paraffin Embedding Protocol describes the processing of the tissues into sections following ethanol fixation. Molecular profiling (MP) is a technique that is used to visualize the global patterns of RNA expression or protein expression in various cell types and disease processes.