Agglutination tests

Universal anti-Rh sera deprived of anti-A or B-antibodies were prepared by contacting A and B-immunoadsorbents with human blood sera. To achieve zero titer in the Coombs agglutination test a portion of immunoadsorbent (80-160 mg) proportional to the initial serum titer (1 8-1 64, 1 ml) is required. The incorporation of A-immunoadsorbent into anti-B sera did not interfere with their titer and vice versa, Under the same circumstances an anti-Rh serum titer is lowered by one step or remains unchanged [125], Properties of this composite sorbent are therefore promising for its use in extracorporal hemisorption processes. 

Quash, G., Roch, A.M., Niveleau, A., Grange, J., Keolouangkhot, T., and Huppert, J. (1978) The preparation of latex particles with covalently bound polyamines, IgG and measles agglutinins and their use in visual agglutination tests./. Immunol. Meth. 22, 165-174. 

Immunological methods Methods such as gel-agglutination tests were introduced many years ago (according to Outcherlony) however they are not sufficiently sensitive. Reversed passive latex agglutination kits (SET-RPLA and TST-RPLA) are presently applied for enterotoxin detection and are more sensitive than gel diffusion (Wieneke, 1988). The ELISA technique is also very popular - toxins are detected via VIDAS STAPH ENTEROTOXIN SET and indirect double sandwich ELISA (Meyrand et al., 1998). 

Apart from antibodies detected by (a) the schizont-infected red cell agglutination test, (b) the agglutination of sporozoites, (c) complement fixation, (d) passive hemagglutination and by the direct and indirect immunofluorescent methods [for review, see reference (V4)], malarial antibodies have also been detected by malarial antigens prepared from heavily infected human placenta, infected human brain, and short-term in vivo cultures of cells from heavily parasitized subjects (Wll) (see Tables 7 and 8). 

Two key steps involved in the traditional methods are antiserum preparation and the agglutination tests. Sera for O determination are produced by immunization of rabbits with cultures that have been heated at 100°C for 2 h. Broth cultures or agar plate suspensions heated at 100°C for 1 h are used as antigens for typing. With these two procedures, bacterial agglutination is a very simple and sensitive method for qualitative O antigen determination. 

Titer is the term used for the results of serological tests (degrees of dilution in agglutination tests), titers are first measurable a minimum of two weeks after the onset of illness, and often not until much later, approximately 30 days following onset. Values begin at 1 100. As the illness progresses, titers slowly increase to 1 400 or more. 

Polystyrene latex particles, 0.2 p, in diameter, have recently been used as immunochemical markers for sceuining electron microscopyS. (SEM). But applications of such a reagent are limited because the lydrophobic surface of the polystyrene particles makes them stick nonspeciflcally to many surfaces and molecules. The same disadvantage applies to agglutination tests. Furthermore, reliance on weak adsorption forces to hold the antibodies on the particles is not always satisfactoryifi and chemical bonding of antibodies to polystyrene particles is virtually... 

Figure 5.6. Percentage of samples from Mycobacterium tuberculosis (TB) patients and healthy controls exhibiting different degrees of agglutination when tested using the conventional slide prooedure or the US-enhanced latex agglutination test. (Reproduced with permission of Elsevier, Ref [76].)...

This situation is similar to that observed in saliva, where the passage of serum antibodies into the salivary secretion has been demonstrated (E5). When antibodies were present in serum of some healthy subjects, antibodies to various bacteria in saliva were found with hemagglutination and bacterial agglutination tests. The presence of these antibodies in saliva may be correlated with the finding of y-globulin in this secretion (E5). 

Clostridium difficile can be cultured from the stool, and toxins A and B can be assessed by different techniques (116). The most accurate method is still a cytotoxin tissue culture assay. This detects the cytopathic effect of cytotoxin B, which can be neutralized by Clostridium sordellii antitoxin, but it takes 24 8 hours to show a result. Alternative tests that produce faster results have been developed. A latex agglutination test lacks sensitivity and specificity, and does not distinguish toxigenic from non-toxigenic strains. An enzyme immunoassay for toxin A may be an acceptable alternative to the cell cytotoxin assay and the results are rapidly available. A dot immunobinding assay has not yet been extensively studied (164). 

Various antibiotics, including azlocillin, aztreonam, cefur-oxime, ceftazidime, chloramphenicol, colistin, flucloxacil-lin, gentamicin, imipenem, meropenem, piperacillin, tazobactam, temocillin, and ticarcillin, were incubated with this patient s serum. Only piperacillin and piperacillin -I- tazobactam caused agglutination in an indirect agglutination test. The authors concluded that the hemolytic anemia had been caused by piperacillin. 

Figure 5.5. Agglutination test for Brucella abortus antibodies.9 [Reprinted, with permission, from E. Benjamini, G. Sunshine, and S. Leskowitz, Immunology A Short Course, 3rd ed., Wiley-Liss, New York, 1996, pp. 115-118. ISBN 0-471-59791-0. Copyright 1996 by Willey-Liss, Inc.]...

Blood typing is one common application of the agglutination test.10 Human erythrocytes may possess either or both of epitopes A and B on their surfaces. Individuals possessing only epitope A have Anti-B in their serum, while individuals possessing only epitope B on their erythrocytes have circulating Anti-A. Some individuals have neither epitope, and both antibodies present, while others have both epitopes, and neither antibody. Table 5.2 lists the four major blood groupings, and the epitopes and antibodies present in their serum. 

An agglutination test for a bacterium was performed on serial dilutions of a freshwater sample. Using dilution factors of 1 1 to 1 512, the results showed the appearance of an agglutination zone and a zone of antibody excess, but no prozone was observed. Was the bacterium present Why was no prozone observed ... 

Carson SA, Reiher J, Scommegna A, Prins GS. Antibody binding patterns in infertile males and females as detected by immunobead test, gel-agglutination test, and sperm immobilization test. Fertil Steril 1988 49 487-92. 

Most laboratories that offer PG testing use a quahtative rapid agglutination test (AmnioStat-FLM, Irvine Scientific, Santa Ana, Calif.) that uses less than 0.5 mL of amniotic fluid. The protocol is as follows 25iaL of amniotic... 

Garite TJ, Yabusaki KK, Moberg LJ, Symons JL, White T, Itano M, et al. A new rapid slide agglutination test... 

Halvorsen PR, Gross TL. Laboratory and clinical evaluation of a rapid slide agglutination test for phosphatidyiglycerol. Am J Obstet Gynecol 1985 151 1061-6. 

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