53 votes
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Are the antibodies developed by differing vaccines still the same?

Due to the nature of the immune system, even people who receive the same vaccine will have a different set of antibodies. Our immune systems generate a vast number of essentially random recognition ...
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30 votes

Is antivenom fatal?

1. Synopsis I'd like to preface this by saying don't randomly use medicines without a doctor's advice. It's fairly unlikely antivenom would cause you any harm but in some cases, antivenom could be ...
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  • 1,495
11 votes
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It is possible for person with AIDS be negative for HIV antibodies?

Usually an antibody test against HIV is positive three month after the infection. Before this time a test can only be done with molecular biology methods as PCR. However, it is possible, that patients ...
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8 votes
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What is the beneficial function of IgE antibody?

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, ...
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8 votes
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Why aren't the antibodies in the mother's milk digested by the infant's digestive system?

Demers-Mathieu et al. 1 used ELISA to quantify immunoglobulin concentrations from milk after 2 hours of digestion in the stomachs of preterm-delivered and term-delivered infants. From the abstract: ...
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  • 7,214
6 votes
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What is a protective epitope?

Lets define the nomenclature first: An antigen is a large structure (protein, virus, bacteria and so an) which is recognized by the immune system as foreign. The word antigen derives from the ...
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6 votes
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IgA complement activation

I found some reports on it (like reference 1) but there is an oddly little amount of publications on this topic. then I found this review in Mucosal Immunology (reference 2, interesting to read) which ...
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6 votes

Can you Transfer Cancer Between People via Saliva or other Bodily Fluids?

Although transmissible cancer has been found in some species, such as Tasmanian Devils and clams, it is quite rare in most species. Certain viral and bacterial agents that cause cancer, however, can ...
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  • 2,373
6 votes
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How plasma cells switches secreting different Ig classes?

In T-dependent antigen recognition, the B cell can switch the isotype by first altering the heavy chain gene. This is driven by Tfh cells. The specific cytokine stimulating the class switch determines ...
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  • 8,031
6 votes
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Why don't phagocytes eliminate mutualistic foregin organisms residing in our body?

Molecular context is important here. E.coli in your colon is OK with the body, it is taken up by phagocytes as part of normal "surveillance". Your immune system will learn and gain "tolerence" to ...
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  • 847
6 votes
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How do scientists discover a new antigen and its epitope?

Okay, you have a few questions building on top of each other (rephrased the questions for clarity): How do scientists discover a new antigen? There are multiple ways to this, which are applied for ...
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  • 4,296
5 votes
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Antibodies stored in freezer instead of fridge

Most IgGs should be fine when stored in the freezer. Freezing at -20 or -80 in small aliquots is the optimal storage condition. Ali-quoting minimizes damage due to freezing and thawing, as well ...
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  • 2,268
5 votes
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Why Rh conflict happen but no ABO conflicts?

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 ...
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  • 7,057
5 votes
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Complementarity Determining Regions (CDRs)

The paratope is the part of an antibody that binds the epitope on the antigen. The CDRs (heavy chain CDRs shown below) are part of the structure of the variable domain, and contain the hypervariable ...
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5 votes
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What is A in IgA?

The letter suffix in the name or abbreviation of an immunoglobulin specifies which type of "heavy chain" the immunoglobin contains. The heavy chain is the large polypeptide (amino acid chain) found in ...
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5 votes
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After getting fully vaccinated for HBV why does the antiHBs titer last for so long?

There is such a thing as memory plasma cells, discovered only relatively recently. Here is a review from 2010 discussing them, here is another review from 2012, and here is a pre-publication ...
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5 votes

Where does the number 67 in the nuclear protein/antigen Ki-67 come from? Why not 66 or 68?

From Wikipedia: "The name is derived from the city of origin (Kiel, Germany) and the number of the original clone in the 96-well plate".
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5 votes

What does it mean to be a fully human monoclonal antibody?

I found this small article that seems to cover all your questions: https://www.sciencedirect.com/topics/medicine-and-dentistry/human-monoclonal-antibody Summary: Being considered a human monoclonal ...
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  • 1,260
5 votes
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How to filter out the antibody light chains into kappa and lambda types on the PDB website?

The instructions are as follows. Go to the RCSB PDB Webite. Under the search bar, click Browse by Annotations. Click the blue tab labeled ...
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5 votes

Why are there so few full-length antibody structures?

There IS a problem! In a previous version of this answer I focussed on various historical, technical, goal-related and commercial reasons for the predominance of structures of antibody fragments (Fab ...
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4 votes
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Synthesis of immunoglobulin Fab fragments: Where can I learn about Fab?

For the generation of Fab-fragments antibodies, (possibly genetically modified) which can be made in large quantities by cells or animals, are used. Antibodies as a whole are not synthesized. The ...
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4 votes
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Calibration curve for single radial immunodiffusion

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 ...
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4 votes
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Are there any disadvantages to HRP conjugated PRIMARY antibodies

You can compare directly coupled antibodies to the classical indirect primary-secondary systems: Directly coupled antibodies Advantages: quicker workflow as only one antibody is used eliminates the ...
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4 votes
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Western blotting with multiple antibodies

What you can do depends on your proteins: If both proteins (your target protein and the loading control) are seperated far enough, you can detect both of them in the same step by adding both primary ...
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4 votes

Antibodies stored in freezer instead of fridge

You don't specify which temperature of freezer you're talking about. Antibody can be stored at -80 for long time, but needs to avoid freeze and thaw process. Some people store aliquot of antibody in -...
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  • 355
4 votes
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Is a variable domain in immunoglobulin's heavy chain different from the one in light chain?

You are correct. In an IgG antibody, there are a total of four protein chains — two identical heavy chains, and two identical light chains, each heavy pairing with a light to form one of the two ...
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  • 14.7k
4 votes

How do scientists discover a new antigen and its epitope?

I would like to just add to Nicolai answer. What is an antigen ? First, and Nicolai said this, but I just want to make it clear, an antigen is anything that antibodies bind. That is distinct from and ...
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4 votes

Can multiple antibodies bind the same antigen?

Not only is it possible for multiple antibodies to bind a single antigen, when that happens, it's more likely to trigger a full immune response. Here's a description of the concept from a company ...
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  • 8,671
4 votes
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What does it mean to be a fully human monoclonal antibody?

Following technquies are used for developing fully human monoclonal antibodies: Complementarity-determining region (CDR) engraftment: This method is performed by preparing cDNA library. CDRs are ...
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3 votes

Can we use the HIV antibody test to detect HIV in newborns?

The rapid screen usually tests the oral mucosa by swabing the inside of the cheek and checking for the presence of anti-HIV envelope antibodies. Although the precise target of these antibodies seems ...
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