What are ELISA readers?
An ELISA reader is an instrument that is used to read the fluorescent, chemiluminiscent, or chromogenic response of the ELISA in a 96-well plate. The instrument is designed to fit standard 96-well plates, and will provide quantitative information about the extent of the response for each individual well of the plate.
How do fluorescent plate readers work?
The emission system of the plate reader uses polarizing filters to analyze the polarity of the emitted light. A low level of polarization indicates that small fluorescent molecules move freely in the sample. A high level of polarization indicates that fluorescent is attached to a larger molecular complex.
What is ELISA plate?
ELISA (enzyme-linked immunosorbent assay) is a plate-based assay technique designed for detecting and quantifying soluble substances such as peptides, proteins, antibodies, and hormones. Other names, such as enzyme immunoassay (EIA), are also used to describe the same technology.
How are ELISA results read?
Calculating concentration of target protein in the sample To determine the concentration of each sample, first find the absorbance value on the y-axis and extend a horizontal line to the standard curve. At the point of intersection, extend a vertical line to the x-axis and read the corresponding concentration.
What is the difference between absorbance fluorescence and luminescence?
The main difference between fluorescence and luminescence is that luminescence describes any process where photons are emitted without heat being the cause, whereas fluorescence is, in fact, a type of luminescence where a photon is initially absorbed, which causes the atom to be in an excited singlet state.
What is the purpose of a plate reader?
A microplate reader is a laboratory instrument that is used to measure chemical, biological or physical reactions, properties and analytes within the well of a microplate. A microplate consists of small wells in which separated reactions take place.
What is OD in plate reader?
OD is defined as the logarithmic ratio between the intensity of light hitting a sample and the intensity of the light transmitted through the sample. Alternatively, transmission, the portion of light that passes the sample, can also be used.
What is ELISA plate made of?
ELISA Plates Flat-bottomed, 96-well plates, made from polystyrene or polyvinyl chloride, are used in the vast majority of ELISA assays. Alternatively a strip well plate can be used.
How do you present data on ELISA?
Best way to represent an ELISA result is to report exact concentration as calculated against some standard by using OD values. That will represent the true difference. Sometimes, OD values can be confusing.
What is microwell?
microwell (plural microwells) A microscopic well; especially one of a large array on a specialized microscope slide.
Why do we measure OD at 600 nm?
Why do we take OD at 600 nm? The reason for measuring optical density at 600 nm is because this is a known wavelength that minimizes cell damage and growth, and is not destructive in nature.
What is a lag phase?
Lag phase is the most poorly understood growth phase, primarily because of a lack of data that describe the underlying physiological and molecular processes. It has been assumed that lag phase allows the adaptation required for bacterial cells to begin to exploit new environmental conditions (70).
What is special about ELISA plate?
ELISA Assay Technology is one of the most sensitive and reproducible plate-based technologies available to detect and quantify the presence of specific substances in a complex liquid. The assay you can set up is rapid, simple to perform and easy to automate.
What is the principle of ELISA test?
Principle of ELISA Test. Most ELISA methods developed for the detection of antigen or antibody consist of use of corresponding antibody or antigen in question which is firmly fixed on solid phase, such as plastic surface of polyvinyl plate or polystyrene tube.
What is the principle of ELISpot?
The principle of an ELISpot is similar to a sandwich ELISA assay, whereby a plate is coated with capture antibodies. Cells are then incubated in the ELISA plate for up to 3 hours, this can depend on application. Cytokines produced by the cells are then bound by the capture antibody immobilized onto the ELISA plate.
How is antigen immobilized in Elisa?
In an ELISA assay, the antigen is immobilized to a solid surface. This is done either directly or via the use of a capture antibody itself immobilized on the surface. The antigen is then complexed to a detection antibody conjugated with a molecule amenable for detection such as an enzyme or a fluorophore. Figure 1.
How does a direct ELISA work?
In a direct ELISA, the antigen is immobilized to the surface of the multi-well plate and detected with an antibody specific for the antigen The antibody is directly conjugated to HRP or other detection molecules.