References Lev
1. Shirahama, H. Takeda, K. Suzawa, T. Adsorption of bovine serum albumin onto polystyrene latex effect of coexistent electrolyte anions. J. Colloid Interface Sci. 1987, 109, 552-556. 2. Shirahama, H. Suzawa, T. BSA adsorption onto HEMA copolymerized latex. J. Colloid Interface Sci. 1985, 104, 416-421. 3. Shirahama, H. Shikawa, T. Suzawa, T. Participation of electrolyte cations in albumin adsorption onto negatively charged polymer latices. Colloid Polym. Sci. 1989, 267, 587-594. 4. Okubo, M....
Ii Magnetic Separation
Magnetic particles have been used as support for the separation, selective isolation, and purification of molecules 32 . For example, in biomedical diagnostics, they can replace the cumbersome steps of centrifugation or filtration 32-34 . The major techniques all involve chemical grafting of biomolecules onto magnetic beads to target specific separation of captured biomolecules or of analytes 29 . Since magnetic supports can be separated from solutions containing other species e.g., suspended...
Ii Indirect Biospecific Interactions Of Viral Particles With Latex
Stable latex particle reagent can be used to diagnose a variety of infectious diseases, such as rotavirus, adenovirus, and canine parvovirus CPV infections. Indeed, polystyrene beads latex particles are agglutinated by antigen when coated with antibodies. The principle of the latex agglutination LA test is shown in Fig. 1. Briefly, latex microspheres coated with specific antibodies react in the presence of the antigen. A positive reaction is characterized by macroscopically visible...
B Immunoglobulin Adsorption
The literature concerning the study of immunoglobulin G adsorption at solidliquid interfaces has a long and confusing history 20,27,28 . We note specifically that 1 experimental adsorption isotherms performed in different laboratories on quite similar systems often conflict and 2 minor changes in experimental conditions pH, ionic strength, temperature may result in major differences in the measured adsorption. These studies are difficult due to the complex interactions involved, and they...
III COVALENT COUPLING A Why Attach Covalently
One of the several advantages for the selection of latex particles as solid support for immunoagglutination tests is that latex may be custom synthesized to fit the needs of a given application. A wide variety of monomer combinations may be chosen to produce latex with desired surface characteristics. In this way, reactive groups can be incorporated into microspheres by an emulsion copoly-merization process in which, for example, one monomer is styrene and the other is methyl methacrylate,...
BProtein Adsorption on PNIPAM Microgel Spheres
Monodispersed, submicrometer poly NIPAM microgel particles were first obtained by Pelton et al. 10 . Onto such latex particles was adsorbed albumin IEP 4.9 and globulin IEP 6.8 at different temperatures 20 C and 45 C 11 . The adsorbability of proteins onto poly NIPAM microspheres was found to depend on temperature. Below the LCST of poly NIPAM or the volume phase transition temperature of poly NIPAM particles in an aqueous medium, that is, around 32 C, the particles adsorbed less protein. This...
I Introduction Tlp
Recent years have heralded an increase in the use of clinical diagnostic methods involving immunological procedures because they are specific and have high sensitivity. Of the many heterogeneous and homogeneous immunological assay methods available, those based on the agglutination of latex particles continue to be widely used in biology and medicine for the detection of small quantities of an antibody or antigen in a fluid test sample. Some advantages of these assays are that the procedures...
A Colloidal Stability
One of the basic requirements for a protein-latex complex to be applicable to clinical diagnostics is colloidal stability under immunological conditions. However, as indicated in the introduction, the most serious problem in latex immunoagglutination assays is that the system can lose its colloidal stability after antibody adsorption step. This low colloidal stability of latex-antibody complexes in the reaction medium may provoke the nonspecific agglutination of particles. The isoelectric point...
References Xzx
1. Singer, J.M. Plotz, C.M. Am. J. Med. 1956, 21, 888. 2. Bangs, L.B. Amer. Clin. Lab. News 1988, 7 4A , 20. 3. Ortega-Vinuesa J.L., Molina-Bolivar J.A., Hidalgo-Alvarez R. J. Immunol. Meth. 1996, 190 1 , 29. 4. Newman, D.J. Henneberry, H. Price, C.P. Ann. Clin. Biochem 1992, 29, 22. 5. Malcata, F.X. Reyes, H.R. Garcia, H.S. Hill, C.G., Jr. Amundson, C.H. J. Am. Oil. Chem. Soc. 1990, 67, 870. 6. Karlsson, R. Michaelsson, M. Matson, L. J. Immunol. Meth. 1991, 145, 229. 7. Haynes, C.A. Norde, W....
C Immunomagnetic Separation of Bacteria
Immunomagnetic separation is based on the specific antigen-antibody reaction common to all of the immunoassays presented above. The immobilization of antibodies on a solid phase spurred the development of sandwich tests or ELISA 38 . Selective separation is a function of the specific epitope of the biomolecule under consideration the efficacy in term of reactivity of the immobilized antibodies on the surface of the magnetic particles depends primarily on their orientation on the surface of the...
II THE AGGREGATION PROCESS A Characteristics of Homocoagulation
From numerical studies, irreversible aggregation processes may be considered as being diffusion or reaction limited 16,20 . For aggregation processes result ing from collisions between particles presenting surface site-ligand complexes, the frequency of efficient collisions, which depends on the surface density of active sites as expressed by the relationship of La Mer, has to be taken into account 21 . The occurrence of inefficient collisions leads the aggregation between incompletely coated...
B Pregnancy Test
The bare latex was a polystyrene latex from Rhone-Poulenc having a diameter of 0.8 pm and bearing both sulfate and carboxylate surface groups. The density as determined from titration was 4.1 pC cm2 for the sulfate groups and 6.73 pC cm2 for the carboxyl groups. The carboxyl groups of the latex particles were treated with the water-soluble activating agents N-hydroxysulfosuccinimide and 33,34 . The particles were then centrifuged and washed with the buffer Tris 0.1 M at pH 8.5 to eliminate...
Contributors
Julio Battistoni Facultades de Qu mica y Ciencias, Instituto de Higiene, Montevideo, Uruguay Michael A. Brook McMaster University, Hamilton, Ontario, Canada S. Tolga Camli Hacettepe University, Ankara, Turkey Jhunu Chatterjee FAMU-FSU, Tallahassee, Florida, U.S.A. Patrick Couvreur Universite de Paris Sud, Chatenay-Malabry, France Thierry Delair CNRS-bioMerieux, Lyon, France Frantz S. Deschamps Mainelab S.A., Angers, France Catherine Dubernet Universite de Paris Sud, Chatenay-Malabry, France...
B Characteristics of Heterocoagulation
Heterocoagulation of latexes of types A and B implies that collisions involving identical particles do not lead to aggregation, successful collisions being those involving A and B particles. If each collision between suitable particles systematically leads to interparticle sticking, the process is diffusion limited. On the contrary, when chemical reactions are required before sticking succeeds, the FIG. 1 Representation of the variation of the exponents w O , z and T as a function of the degree...
Preface
Colloids latexes and hybrids provide suitable solid-phase supports as a carrier of various molecules, biomolecules, and active agents. In fact, diverse and varied particles have been developed and explored in numerous biomedical applications. In biomedical diagnostic, the immobilization adsorption, covalent grafting, and specific interactions of biomolecules such as proteins, antibodies, peptides, nucleic acids, bacteria, and viruses onto colloidal particles is of paramount importance. In...