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7

No, they are of course not there to cause allergies. It is thought (although not directly proven in human) that IgE is important to fight parasites and worms. They bind to antigens from the parasites, which leads to the secretion of histamines. This causes a local immune reaction (which also is a problem in allergies) which is helpful to fight the parasites. ...


6

Maybe WB is easier for them to test? In general, however, my recommendation is to check if they provide refs to paper using those antibodies and look at the images on the paper. Be careful putting your trust in the supplier's pictures, I have seen obviously photoshopped images on commercial websites. Also always double-check the referenced papers, as ...


5

I worked for a long time at a leading high-quality antibody company, so I'll try and share some of my experiences with you. The process of making a highly specific antibody (I'll focus on monoclonals) has three important parts - antigen design and immunization, cloning and subcloning, and screening/validation. Each part is crucial on its own, and the better ...


4

The key feature of type O blood as "universal donor" is that the incoming red blood cells have neither A nor B antigens and so the resident antibodies (anti-A , anti-B) will not react with them. Since transfusions are carried out with packed red blood cells the plasma antibodies of the donor don't matter - they will not be introduced into the recipient.


4

It is! Here is an amazing review from 2011 that literally has all the answers. I'm not kidding, all of them. I would marry this review if I could.1 It also includes information on other animals. The main takeaway is that IgA from milk is not readily absorbed by the infant body. Secreted IgA is mainly to provide a protective coating for the mucosa while ...


4

It happens, but it is very rare. Anti-A and Anti-B antibodies are IgM type. They do no cross the placenta. Sometimes IgG can be produced and lead to the hemolytic disease of the newborn. Anti-D antibodies are IgG type and can pass through the placenta.


3

Within an organism, antibodies which bind to other antibodies in the body would be eliminated during clonal selection. They are not made by the body after that period, which is in the first few months of life. Such antibodies would have to be introduced from the outside. Many have been designed or engineered for biotech and as therapeutics.


3

Making antibodies is mostly nothing you do with transgenic microorganisms. To make an antibody you first have to immunize an animal with the correct antigen. This includes have an animal facility where you can keep animals under clean conditions. If you are looking for polyclonal antibodies (meaning a whole bunch of different antibodies with different ...


3

Immunopanning is essentially an immunoprecipitation (IP) of cells using an antibody immobilized to a solid surface, like a cell culture plate. Conventionally, an IP is performed using small agarose or magnetic beads (~50 to 150μm in size) conjugated to an antibody or Protein A/G, and can pull down individual proteins, protein complexes, and/or nucleic acid ...


3

When testing an antibody for an imaging application, it is almost always a good idea to test it in another application like ELISA or Western blotting to see if it binds the target of interest. For example, try to find high- and low-expressing cell lines, load equal amounts, and see if there is a difference in signal at the expected molecular weight. Check ...


3

The processes are called gene rearrangement and somatic hypermutation, and are used by maturing B-cells to generate very (very) large amounts of diversity in the antibody repertoire. If your institution has access, this great article in Annual Reviews in Immunology has all the details, or you can read about it in Janeway (slightly outdated edition). ...


3

I'll preface this by saying that I'm talking about antibodies of mammalian/human origin, consisting of two identical heavy and two identical light chains disulfide-bonded into the classic antibody structure: It is possible to produce antibody-like molecules known as single-chain antibodies, including single-chain variable fragments (scFv) in bacteria and ...


3

Antibodies for WB and for IF have fundamentally different requirements for the epitope structure. Antibodies for WB recognize denatured structures extended by SDS treatment. Antibodies for IF often will need to recognize a native-like structure. Depending on the supplier, some will have lots of antibodies for IF. I suggest looking around some more.


3

I don't believe that the Isotype Control Antibody makes the antibody bind more specifically but rather ensures that your signal is specific to your antibody. The Isotype Control Antibodies tend to bind to the non-binding domain of the antibody, typically the constant (Fc) domain. By measuring the concentration of the control antibody, you can determine what ...


3

Antibodies are simply proteins and like any other protein have a relatively short "life", so after clearing out an infection, they are not retained for long (most of them anyway). What the body keeps is memory cells which can produce a much more rapid response if they come in contact with the same pathogen again. You could see it as a selective process: the ...


3

ELISA is Enzyme-Linked ImmunoSorbent Assay (capitalisation to point out source of acronym). You can read about the various ways to do an ELISA here. In your case this was probably an indirect ELISA. All ELISA techniques make use of the fact that proteins stick to plastic. In your case the protein components of the saliva, including the virus (the viral ...


3

When the radial immunodiffusion method is used to measure antigen concentrations in samples, a plate or slide is set up using agarose containing an antibody or antiserum. Holes are punched out of the agarose to form wells into which antigen is dispensed. The antigen diffuses out into the agarose and when the antigen/antibody ratio is favourable an ...


2

While bobthejoe/leonardo's answers are correct, you also need to be aware of the quality and limitations of isotype controls. You need to pick your source very carefully, as extensive testing (at my former company) has shown that some isotypes stick non-specifically under certain conditions or with certain samples. For example, we found that one common ...


2

Like any other protein, antibodies will aspecifically bind nitrocellulose or PVDF membranes, but any other protein present in your antibody preparation will also do. Depending on the antibody class, more specific binding can be obtained with protein A or protein G, that recognize the Fc domain. It's usual to have protein A/G immobilized on a stationary ...


2

This article on the University of Kentucky website is pretty good, it seems the cancer cells hide because they do not express CD80, a co-stimulating molecule. Co-stimulating molecules are often necessary for an effective immune response. This is a big part of the article and I think they do a good job of explaining it so I'll just quote: "People once ...


2

The short answer is that antibodies are proteins like any other, and if an antibody from a foreign source is injected it can result in an immune response. This is, of course, exploited in the production of secondary antibodies for use in research (e.g. goat anti-rabbit IgG is a goat antibody that recognises rabbit IgG). Because of this, therapeutic ...


2

Both are technically correct. Here's a review that goes into some detail about the process: IgG Placental Transfer in Healthy and Pathological Pregnancies. It's worth a read if you're interested in the subject. In particular, it cites a study of immunoglobulin transport which: demonstrated a continuous rise in IgG levels in the fetal circulation ...


2

If you have an antibody that is directed against, for example, a bacterial surface protein, then by mixing the bacterial cells with the antibody at a suitable stoichiometry you could observe clumping of the cells as the antibody molecules essentially cross link the cells together. This would be an example of using an agglutination (clumping) assay with a ...


2

Let's clarify the terms. An antigen is a molecule that can be associated with a particular substance (virus, pollen, dander.) When an immunoglobulin or antibody recognizes an antigen it binds to a specific epitope. An antibody recognizes an epitope using its paratope. Some antigens have multiple epitopes; this means that different antibodies can ...


2

The root of the problem in this case are not the antibodies but the antibody producing cells (APC). They are capable of producing vast amounts of antibody, so I doubt that this approach would be successful. The problem with targeting these APCs is, that you have to know exactly which are the ones which cause the problem, if you want to target them ...


1

I'm not sure that I have understood the question but ... HbeAg is a secreted variant of HbcAg (the core antigen of HBV). Unlike HbcAg, HbeAg is found in the blood. I believe that it is produced as a result of a splice variant of the corresponding RNA. The phenomenon described in these Figures is an example of seroconversion. Before seroconversion the ...


1

1) The secondary response requires CD4+ T cells to activate memory B cells. That first paper actually gives some evidence that some of the rapidity could arise because T cells and memory B cells are in very close proximity to each other in germinal centers. 2) Yes. The affinity of antibodies increases during the initial infection, both through isotype ...


1

In general the immune system sees the world in very simplistic terms: Self vs Non-Self. Ideally, threats to the health of the animal are all non-self and can be attacked strongly. Whereas self cells and proteins are tolerated - effectively invisible to the immune system. Cancer is a particularly insidious disease because it arises, not from the outside ...


1

@MattDMo hit the highlights, but I wanted to comment on the creation of libraries of anbitodies for screening in bacatera. But there has been interest in nanobodies - the antibodies of camelids (llamas and camels) have only one chain, which makes the idea of heterologous expression in bacteria even simpler.


1

It is unlikely that an antibody would bind another antibody within just the human species. Human antibodies which bind to the human Fc portion cannot exist as they would be filtered by self tolerance mechanisms (as these B cells would be chronically activated or would the T cells that would be required for costimulatory help allowing the B cells to class ...



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