Technology
This is a method (named after the Danish bacteriologist, Hans Christian Gram) for staining and identifying bacteria. It is based on the differential retention of a crystal violet-iodine complex within the cell membrane. Gram-positive organisms will appear blue-black or purple while Gram-negative organisms will appear red.
Diagnostic Methods
Technology
An in vitro assay that is used to determine whether antibodies present in serum samples will prevent hemagglutination in a cell culture plate containing red blood cells and influenza virus.
Diagnostic Methods
Technology
Hematoxylin-and-eosin, or H&E, is a routine staining procedure of tissue sections. This staining method uses two separate dyes, one staining the nucleus and the other staining the cytoplasm and connective tissue. Hematoxylin is a dark purplish dye that stains the chromatin (nuclear material) within the nucleus. Eosin is an orangish-pink to red dye that stains the cytoplasmic material including connective tissue and collagen.
Diagnostic Methods
Technology
Frequently referred to simply as HPLC, this form of column chromatography is used frequently in biochemistry. The analyte is forced through a column by liquid at high pressure, which decreases the time the separated components remain on the stationary phase. Less time on the column then translates to narrower peaks in the resulting chromatogram and thence to better selectivity and sensitivity.
Diagnostic Methods
Technology
A type of chromatography assay in which an antibody-conjugate is passed over an immobilized antigen, giving a visual indication of positive or negative result.
Diagnostic Methods
Technology
A method for the detection of proteins or antigens on samples of cells that are grown in monolayers or in suspension and deposited on slides using antibodies or other biomolecules that bind the target and can be visualized through a chemical process.
Diagnostic Methods
Technology
A quantitative technique used to detect and estimate the concentration of an antigen by measuring the precipitation which is formed as a result of the interaction of the antigen and an antibody at optimal concentration.
Diagnostic Methods
Technology
A laboratory testing method to determine the concentrations of immunoglobulins in the blood.
Diagnostic Methods
Technology
An enhancement of immunoelectrophoresis in which a series of post-electrophoretic gel slabs are layered with cellulose-acetate gels saturated with specific antibodies. The resulting antigen-antibody complexes fixed on the second gel may then be stained, allowing sensitive and specific qualitative visual identification of paraproteins by electrophoretic position. It can be used to identify specific proteins in the blood or urine. It has greatest application in the identification and monitoring of monoclonal proteins that are produced in conditions like Waldenstom's macroglobulinaemia and multiple myeloma.
Diagnostic Methods
Technology
Immunohistochemical staining techniques allow for the visualization of antigens via the sequential application of a specific antibody to the antigen (primary antibody), a secondary antibody to the primary antibody and an enzyme complex with a chromogenic substrate. The enzymatic activation of the chromogen results in a visible reaction product at the antigen site. The specimen may then be counterstained and coverslipped. Results are interpreted using a light microscope and aid in the differential diagnosis of pathophysiological processes, which may or may not be associated with a particular antigen.
Diagnostic Methods
Technology
An immunological procedure in which antibodies are coupled with a peroxidase molecule. Following localization via the antibody, the peroxidase is reacted with a corresponding substrate to produce a product which can be seen with a light microscope.
Diagnostic Methods
Technology
Use of a DNA or RNA probe to detect the presence of complementary sequences in chromosomes, cells, or tissues.
Diagnostic Methods