Toxins antibodies using

Another way of utilizing SPDP is to again activate the antibody to create the pyridyl disulfide derivative, but this time thiolate the toxin component using 2-iminothiolane (Chapter 1,... 

Figure 21.15 A periodate-oxidized dextran polymer may be reacted with both an antibody and an intact toxin component using reductive amination to form a multivalent immunotoxin complex.

Polyclonal antibody preparations have been used for several decades to induce passive immunization against infectious diseases and other harmful agents, particularly toxins. The antibody preparations are usually administered by direct i.v. injection. While this affords immediate immunological protection, its effect is transitory, usually persisting for only 2-3 weeks (i.e. until the antibodies are excreted). Passive immunization can be used prophylactically (i.e. to prevent a future medical episode) or therapeutically (i.e. to treat a medical condition that is already established). An example of the former would be prior administration of a specific anti-snake toxin antibody preparation to an individual before they travel to a world region in which these snakes are commonly found. An example of the latter would be administration of the anti-venom antibody immediately after the individual has experienced a snake bite. 

Another variation to conjugate antibodies is to use bispecific antibodies. These are produced using chemical means and recombinant techniques to fuse separate hybridomas into a hybrid hybridoma (Fig. 4.6). Bispecific antibodies use one arm of the Fv to target the antigen or tumor cell and the other arm carries the effector molecule of toxins, radioisotopes, or other drugs. 

There are two types of immunisation passive and active. Passive immunisation involves transfer of antibodies formed in response to an antigen in one individual to another. Such antibodies were first produced in animals but now most antibodies used for passive immunisation are of human origin, which minimises allergic reactions. This form of immunisation gives immediate protection but it does not last very long, since the antibodies are soon degraded in the body. It is used, for example, to protect against tetanus, rabies and the toxins in snake venom. 

Figure 10.5. Upon transformation, cancer cells often express unique surface antigens termed tumour surface antigens (TSAs). Antibodies raised against these will selectively bind the tumour cells. The antibody used may be unconjugated or conjugated to a drug, toxin or radioactive tag...

Human tetanus immunoglobulin is a solution of human immunoglobulin G (IgG) containing a high level of anti-tetanus toxin antibodies. It is prepared from the plasma of screened, human donors immunised against tetanus toxin and is administered by intramuscular injection. The product also contains isotonic sodium chloride, glycine, as a stabiliser, sodium acetate and a small amount of sodium hydroxide used to maintain pH. The product is generally well-tolerated. 

Several research groups have reported antibodies for aflatoxins and other mycotoxins (27). Commercial kits for aflatoxin detection in various substrates have been announced. The introduction of such kits will permit on-site detection of aflatoxins to be confirmed immediately rather than having to wait for analytical results from a remote laboratory following detection of fluorescing materials in a commodity. Since aflatoxins and other microbial toxins have a number of structural variations, the antibodies used in their analysis must be carefully selected to assure that the proper compounds are being detected and accurately measured. 

Since then, many improvements have been made on the format and antibodies used in the test in order to minimize error, " however, there does still exist some variations and nonspecific binding for different toxins. 

Detection of snake toxins and toxin antibodies in body fluids remains very important for the identification of the biting species and the correct management of envenomation. As snake venoms consist of a complex mixture of pharmacologically active peptides and proteins, detection is usually approached by immimological techniques. Radioimmimoassay (RIA) using specific monoclonal antibodies has proved to be highly reliable and sensitive. However, the difficulty of handling radioisotopes and the need of elaborate equipment limit its application in... 

Buoyant silica bubbles were employed as capture substrates in a cholera SERS immunoassay (Schmit et al. 2012). Silica bubbles were silanized and then functionalized with an anti-cholera toxin antibody. Au NPs were used as SERS... 

The sensitivity of the early ELISA methods (51) was in the same range as previous in vitro methods, but increased greatly with the incorporation of amplifier systems (58,64). Specificity has also improved with the preparation of antitoxins against highly purified toxins and use of monoclonal antibodies (64). The reports on the ELCA method describe meticulous preparation of high quality reagents and an exceptionally effective amplification which utilizes the Russell s viper venom factor X activator to initiate the clotting cascade (9,10). Its sensitivity appears to equal or exceed that of the mouse. 

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