Technology
Emission of electromagnetic energy with a shorter frequency (longer wavelength) than that of the incident monochromatic light. Arises from the low probability absorption of quanta with a higher energy than that required for a transition: the difference in energy is emitted as a lower frequency (energy) photon. Allows analysis of vibrational and rotational energy levels using visible incident light.
Diagnostic Methods
Technology
An application of PCR that measures the products generated during each cycle of the polymerase chain reaction process in order to determine the starting amount of template in the reaction.
Diagnostic Methods
Technology
Variation occurring within a species in the length of DNA fragments generated by a specific endonuclease. Such variations are generated by mutations that create or abolish recognition sites for these enzymes.
Diagnostic Methods
Technology
A laboratory procedure in which an RNA strand is first transcribed into a DNA complement and then subjected to PCR amplification. Transcribing an RNA strand into a DNA complement is termed reverse transcription and is done by the enzyme reverse transcriptase.
Diagnostic Methods
Technology
Technique of electron microscopy in which the specimen is coated with heavy metal and then scanned by an electron beam. The resolution is not as great as with transmission electron microscopy, but preparation is easier (often by fixation followed by critical point drying), the depth of focus is relatively enormous, the surface of a specimen can be seen (though not the interior unless the specimen is cracked open) and the image is aesthetically pleasing.
Diagnostic Methods
Technology
A method for collecting tandem mass spectrometry data where an ion of a particular mass is selected in the first stage and a fragmented ion product is selected in the second mass spectrometer stage for detection. Selected reaction monitoring (SRM)-based experiments are generally performed in a triple quadrupole (QqQ) mass spectrometer.
Diagnostic Methods
Technology
Silver Staining or GMS staining is a technique for demonstrating fungi in tissue sections. It is primarily based on staining the polysaccharides in fungal cell wall (From BioGenex).
Diagnostic Methods
Technology
A rapid, simple, visual and sensitive technique for measuring DNA breakage in individual mammalian cells in response to a test agent. A cell is immobilized in agarose and made permeable and the broken DNA migrates out under the influence of the electric field. A damaged cell has the appearance of a comet with a brightly fluorescent cell body and a tail whose length and fluorescence intensity are related to the number of DNA-strand breaks induced by the test agent.
Diagnostic Methods
Technology
A procedure that can determine the nucleotide sequence for all of the RNA transcripts in an amplified nucleotide sample that was derived from a single cell.
Diagnostic Methods
Technology
A novel karyotyping procedure which is based on the simultaneous hybridization of 24 chromosome-specific painting probes labeled with different fluorochromes or fluorochrome combinations. The measurement of defined emission spectra by means of interferometer-based spectral imaging allows for the definitive discernment of all human chromosomes in different colors. (from Schrock et al., Hum Genet 1997:101:255-62)
Diagnostic Methods
Technology
A procedure used to demonstrate nucleotide sequence variations that occur in the same region of DNA between individuals within a species, or between alleles in an individual to detect mutations in various genes, such as oncogenes, tumor suppressor genes, or genes responsible for genetic diseases. The method detects different conformations adopted by partially denatured DNA fragments resulting from their specific nucleotide sequences under denaturing conditions. Denatured single-stranded DNA fragments are allowed to partially renature without formation of double-stranded DNA. The particular conformations adopted by each of the renatured fragments depend on each of their specific nucleotide sequences. The fragments are run on polyacrylamide gels to detect subtle changes in migration due to their particular secondary structures. Resulting fragment band in the gel will misalign if any point mutations are present to alter the conformation.
Diagnostic Methods
Technology
An isothermal, in vitro nucleic acid amplification method that allows primer-directed amplification of a target sequence. It utilizes a primer that can be nicked to create a polymerase start site and a DNA polymerase that will displace a downstream strand as it tracks along the template.
Diagnostic Methods