Vari Fluor 488-Streptavidin

Enzyme-linked immunosorbent assay (ELISA) is a biochemical technology widely used to detect and quantify proteins, antibodies, hormones and other biomolecules. This method uses enzyme-labeled antibodies or antigens to specifically bind to the test substance, and generates a measurable signal through an enzyme-catalyzed reaction. ELISA has the characteristics of high sensitivity, specificity and high-throughput, and is suitable for medical diagnosis, biomedical research and drug development and other fields.

Antibody-based immunofluorescence/immunocytochemistry detects the cellular or subcellular localization of a target antigen by binding a primary antibody to the target and detecting that antibody directly with a fluorophore-conjugated primary antibody or indirectly with a fluorophore-conjugated secondary antibody. Indirect immunofluorescence can amplify signal because multiple secondary antibodies can bind one primary antibody. The assay readout is fluorescence intensity and localization measured by fluorescence or confocal microscopy, and the result reflects antigen distribution only when the antibody has been validated for the target, sample type, fixation condition, and imaging workflow. Antibody specificity must not be assumed from catalog information alone, and appropriate validation or control experiments are required for serious interpretation.

The labeled nucleic acid probe is hybridized with the DNA or RNA on tissues and cells by using the complementary base sequence between the single strands of nucleic acid molecules. The detected DNA or RNA molecules in situ in cells can be displayed by autoradiography, fluorescence detection or enzyme color development.