light Protocols

Category: C. elegans Protocols

At low magnification, dissection microscopes are useful, whereas at higher magnification and resolution, a wide range of optical methods can be used, including differential interference contrast (DIC) optics, phase contrast, fluorescence, polarized light, confocal, and dark field. - [Read Live Imaging of Caenorhabditis elegans: Observation of Nematodes and Data Collection Protocol]

Category: Microscopy Protocols: Confocal Microscopy Protocols

Confocal laser scanning microscopy (CLSM) is a relatively new light microscopical imaging technique which has found wide applications in the biological sciences. The primary value of the CLSM to the biologist is its ability to produce optical sections through a 3-D specimen-e.g., an entire cell or a piece of tissue - that, to a good approximation, contain information from only one focal plane. Article includes principle and applications of confocal laser scanning microscope. - [Read Looking Inside Cells and Tissues by Optical Sectioning with a Confocal Laser Scanning Microscope]

Category: PCR Protocols: Real-Time PCR Protocols

In multiplex real-time PCR, different sets of primers with different labels are used to amplify separate genes from the template DNA in one tube.  This protocol uses LUX (Light Upon eXtension) primers from invitrogen.  FAM (6-carboxy-fluorescein) is used to label the gene of interest, and JOE (6-carboxy-4', 5'-dichloro-2',7'-dimethoxy-fluorescein) is used to label a housekeeping gene as an internal control to normalize between different reactions. - [Read Multiplex Real-Time PCR Protocol]

Category: Microscopy Protocols: Optical Microscopy Protocols

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]

Category: Microscopy Protocols: Optical Microscopy Protocols

Near-field scanning optical microscopy can achieve spatial resolution performance beyond the classical diffraction limit by employing a sub-wavelength light source or detector positioned in close proximity to a specimen. Such a sub-wavelength source usually consists of an aperture at the end of a tapered probe, which functions basically as a wave guide. Includes info.: Fiber Probe Fabrication; Pulling Method; Meniscus Etching; Selective Etching; Apertureless and Alternative Probe Designs etc. - [Read Near-Field Scanning Optical Microscopy: NSOM Probes]

Category: Stem Cell Protocols: Stem Cell Culture Protocols

Describes the steps in detail to isolate and expand neural stem cells in the form of neurospheres from tissue dissections of the post-natal mouse brain. Procedures for the long term passage of neurospheres and the cryopreservation of neurospheres are also provided. In addition to the guidelines and tips for generating neurosphere cultures, we describe the method to prepare neurospheres for analysis by light microscopy. - [Read Neural Stem Cell Culture: Neurosphere Generation, Microscopical Analysis and Cryopreservation]

Category: Cell Biology and Cell Culture: Flow Cytometry Protocols

Paraformaldehyde Fixation of Cells protocol. This fixation method is good for cells labeled by fluorochrome-conjugated antibodies to membrane antigens.  It will stabilize the light scatter and labeling for up to a week in most instances, allowing you to be more flexible in scheduling cytometer time.  Furthermore, it inactivates most biohazardous agents, so it is important from a safety standpoint as well. Iowa University. - [Read Paraformaldehyde Fixation of Cells]

Category: Cytogenetics Protocols

An ideal method of tissue preparation ensures both good specimen morphology and that the target molecules are in the optimum state for probe access and hybridization. DNA:DNA in situ hybridization is usually carried out on chromosome spread preparations where chromosome and nuclei are released from cells and spread on a glass microscope slide. This method yields well separated and enlarged chromosomes with good morphology which can be analyzed in transmitted light or fluorescence microscopes. - [Read Preparation of Chromosome Spreads]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols: Membrane Isolation Protocols

This protocol uses a "light mitochondrial" pellet from a mammalian liver homogenate. The gradient thus has to resolve a variety of denser components (peroxisomes, lysosomes, mitochondria) from the Golgi membranes, which have a low density in iodixanol (1.06-1.09 g/ml) [1]. The protocol is specifically tailored to the purification of Golgi membranes from this pellet and is unsuitable for the isolation or analysis of other organelles present in the light mitochondrial fraction. - [Read Purification of Golgi Membranes from a Light Mitochondrial Fraction in a Self-Generated Gradient]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols: Peroxisome Isolation Protocols

Peroxisomes can be purified in self-generated iodixanol gradients in high yield (80-90%) with no detectable contamination from any other organelle. In iodixanol peroxisomes are the densest of the major subcellular organelles (ρ = 1.18-1.20 g/ml) present in the light mitochondrial fraction from mammalian tissues and cells. - [Read Purification of Peroxisomes in a Self-Generated Gradient]

Category: PCR Protocols: Real-Time PCR Protocols

Protocol uses FAM-(6-carboxy-fluorescein) or JOE-(6-carboxy-4', 5' -dichloro-2',7' -dimethoxy-fluorescein) labeled LUX (Light Upon eXtension) primers, which can quantify 100 or fewer copies of the target DNA in a background of nonspecific templates, over a broad dynamic range of less than 100-107 copies.  It uses uracil deglycosylase (UDG) to minimize the risk of carryover contamination, and includes a melting curve analysis of the product. - [Read Real-Time PCR Protocol]

Category: Microscopy Protocols

Reflected light microscopy is often referred to as incident light, epi-illumination, or metallurgical microscopy, and is the method of choice for fluorescence and for imaging specimens that remain opaque even when ground to a thickness of 30 microns. - [Read Reflected Light Microscopy]

Category: Microscopy Protocols: In Vivo Imaging Protocols

In the past two decades, there have been many revolutions in light microscopy techniques made possible by improvements in optics, detector technology, and computers. Furthermore, there is no indication that the rate of development of new equipment is slowing down. Here we attempt to provide an overview of available options and important considerations applicable to imaging Drosophila cells and tissues. - [Read Selection of Appropriate Imaging Equipment and Methodology for Live Cell Imaging in Drosophila]

Category: Molecular Imaging: Light Microscopy

USE OF THE LIGHT MICROSCOPE. Step by step methodology guide on how to use a light microscope. Veterinary Pathology. Bristol University - [Read USE OF THE LIGHT MICROSCOPE]

Category: Molecular Imaging: Light Microscopy

Very short introduction to light microscopy and digital imaging. Hernan G. Garcia - [Read Very short introduction to light microscopy and digital imaging PDF]

Category: Nucleic Acid Electrophoresis Protocols: RNA Electrophoresis Protocols

Method is used to assess (roughly) the integrity of total RNA samples by visualization of discreet 18S and 28S ribosomal RNAs.  Total RNA is separated by electrophoresis through a 1% agarose gel containing 1.3 ìM ethidium bromide.  Binding of the ethidium bromide to the RNA allows visualization of the separated RNA molecules when the gel is exposed to ultraviolet (UV) light. - [Read Visualization of RNA Preparations on 1% Agarose Gels Protocol]

Category: Microscopy Protocols: Optical Microscopy Protocols

The light microscope allows dynamic biological processes to be imaged in their native (i.e., aqueous) environment with relatively high temporal resolution. However, the diffraction-limited resolution is low. When working at or beyond the diffraction-limited resolution of the LM, a disadvantage of fluorescence imaging is the relatively low signal-to-noise (S/N) ratio of the images. However, this can be increased significantly by video and computer technology. - [Read Watching Molecular Motors at Work by Video-Enhanced Light Microscopy]