IMMUNOBLOT Meaning and
Definition
-
An immunoblot is a laboratory technique used in molecular biology and immunology to detect and identify specific proteins within a biological sample. It is based on the principles of immunodetection, which relies on the specificity of antibodies to bind to their target proteins.
In an immunoblot, proteins are first separated based on their size using a technique called gel electrophoresis. The proteins are then transferred onto a solid support such as a nitrocellulose or polyvinylidene difluoride (PVDF) membrane, forming a protein blot. This blotting step allows for the immobilization of the separated proteins in their original positions.
Next, the membrane is incubated with specific antibodies that recognize and bind to the target protein of interest. These antibodies are often labeled with enzymes or fluorescent molecules, which enable the detection of antibody-protein complexes. The excess antibodies are then washed away, leaving only the specific antibody-protein complexes bound to the membrane.
Finally, a visual or spectroscopic method is used to detect the labeled antibody-protein complexes on the membrane. This can be achieved through substrate addition for enzyme-labeled antibodies, or by fluorescence detection for fluorescent-labeled antibodies. The resulting bands or spots on the membrane correspond to the presence and localization of the target protein within the original biological sample.
Immunoblots are frequently used in research and diagnostic settings to determine the presence, quantity, and molecular weight of specific proteins. They offer a high level of specificity and sensitivity, making them a valuable tool for understanding protein function and identifying disease markers.
Etymology of IMMUNOBLOT
The word "immunoblot" is derived from the combination of two terms: "immuno-" and "blot".
The prefix "immuno-" is derived from the Latin word "immunis", which means "exempt" or "free from". In this context, "immuno-" refers to the immune system or any immune response.
The term "blot" originated from the Middle English word "blot", which initially referred to a mark or a spot. In the context of laboratory techniques, "blot" is used to describe a procedure that transfers or immobilizes proteins or DNA onto a solid support (such as a membrane).
Therefore, "immunoblot" refers to a laboratory technique that combines immunological methods with blotting techniques to study the presence or absence of specific proteins (or antigens) in a biological sample. It is commonly used in molecular biology and diagnostic medicine.
