Primary Antibodies

Primary antibodies are immunoglobulins that bind to a specific antigen of interest. The antigen can be for example a protein, a peptide, a small molecule. A high-quality primary antibody recognizes and binds with high affinity and specificity to purify, detect, and measure the antigen. Using different hosts, such as mouse, rabbit, rat or chicken, primary antibodies are available as polyclonal or monoclonal antibodies, depending on the application. Primary antibodies for commonly studied targets are also available in conjugation with fluorescent dyes or biotin, PE and other molecules.

At antibodies-online.com you will find high-quality primary antibodies with diverse validation data for a large number of targets, reactivities and conjugates.

Featured primary antibodies categories

Popular Primary Antibodies

antibodies-online.com supplies you with antibodies for more than 60,000 targets, for more than 100 different applications and methods, a wide variety of conjugates, reactivities etc. In case you need assistance with finding the right product our team of PhD biologists is looking forward to your request via phone or email to support you in your research work.

Browse our Primary Antibodies by Application

We offer antibodies for more than 100 applications. Below are some of the most requested. If you do not find the method you are looking for, please use our search and filter out the desired products quickly and easily, or contact our customer service.

• Chromatin Immunoprecipitation (ChIP)

  CUT&RUN / CUT&Tag

  ELISA
  Flow Cytometry (FACS)

  Immunocytochemistry (ICC)

  Immunofluorescence (IF)
• Immunohistochemistry (IHC)

  Immunoprecipitation (IP)

  Western Blotting (WB)

We support you with antibodies validated for many other applications such as FLISA, Immunocytochemistry, and more. Use our search to find the right product for you.

Browse our Primary Antibodies by Conjugate

On antibodies-online.com you will find a wide selection of conjugated primaries. Some of the most important conjugates are listed below. By clicking on a link you will get to the corresponding products.

• Alexa Fluor 647

  Alexa Fluor 750

  APC
  Atto 390

  Biotin

  DyLight 488
• FITC

  HRP

  PE

We support you with a wide range of conjugates. Please use our search function or contact our team of biologists if you need help finding your desires product.

Reagents and Tools related to Primary Antibodies

On antibodies-online.com you will find a lot of other tools and reagents for your daily work. Some important categories are shown below.

• Secondary Antibodies
• Isotype Controls
• Buffers

Resources

• Loading Controls
• Introduction to Western Blotting
• What ist Flow Cytometry?
• Protein Tumor Markers - Biomarkers in tumor diagnostics
• Cytokeratins in Tumor Detection
• Our Independent Validation Initiative - Share your antibody validation data and get your money back

Antibody FAQ

What is an antibody?

Antibodies are proteins produced in vertebrates in response to certain substances. Antibodies are an important element of the so-called humoral (antibody-mediated) immunity. They belong to the gamma globulin fraction and are also called immunoglobulins (Ig).

Antibodies are produced by the body when B cells come in contact with a matching antigen. As a result, the B cell is activated and differentiates into a plasma cell that secretes large amounts of antibody. These antibodies are able to specifically bind the antigen which has caused the differentiation of the B cell.

How are antibodies structured?

Antibodies have a common basic structure: each consists of two heavy and two light identical polypeptide chains, linked via disulfide bridges. The heavy and light chains include constant and variable regions. The variable regions of both chains determine the binding domain (paratope) for a specific antigenic determinant (epitope). The epitope is the part of the antigen that is recognized by the antibody. In addition, the constant regions of the heavy chains determine the immunoglobulin class to which the antibody belongs (IgM, IgG, IgD, IgA or IgE). The immunoglobulin class is also called isotype. The various antibody classes are found in different compartments of the body. For example, IgA is present in the saliva while IgG and IgM are found in the blood. In addition, membrane-bound antibodies are also found (e.g.: IgE on mast cells or IgD on B lymphocytes).

What is the function of antibodies?

In the course of an immune response, the antibodies perform various functions. They capture and block invading antigens so that they cannot exert their harmful effect, or they prevent the antigen’s interaction with body cells (e.g. to prevent the penetration of viruses and bacteria into body cells).

Antibodies also opsonize pathogens. In this case the antibody constitutes a marker, e.g. for phagocytes. The phagocytes interact with the constant regions of the antibody in contact and are induced to uptake and digest the pathogen (e.g., a bacterium).

Antibodies may also bind to body cells, thereby causing the so-called NK cells (natural killer cells) to selectively kill the cell. This is useful when a cell is infected with a pathogen (e.g., a virus). Other important functions include the activation of various cell types of the immune system and the complement system.

What are antibodies used for?

Antibodies are used in medicine for diagnostic and therapeutic purposes (e.g. serological tests, diagnosis and follow-up of infectious diseases, passive immunization, etc.). They also offer many possible uses (ELISA, FACS, Western blots, immunohistochemistry, etc.) for research purposes. For these purposes, polyclonal antibodies, monoclonal antibodies or recombinant antibodies are used.