Latex immunoassays: comparative studies on covalent and physical immobilization of antibodies. I. F(ab')2 fragments.
Colloidal particles coated with antibodies are currently used in diagnostic test systems for the detection of antigens in biological fluids. Immobilization is usually carried out by physical adsorption. Covalent coupling of antibodies to particles, however, offers certain advantages. The present research deals with the study of these possible advantages. A sulphonated polystyrene latex has been used to prepare an immunolatex with physically adsorbed antibodies, while a functionalized latex with chloromethyl groups on the surface has been used for the partly covalent coupling of the antibody (F(ab')2 fragments). The immunoreactivity was studied by measuring the variations in scattered light intensity after mixing a solution of CRP antigen and the sensitized latex. The influence on the immunoresponse of the scattering angle (5, 10, and 20 deg), protein coverage and storage time have been studied for both systems.
Molina-Bolívar
J A
JA
Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Granada, Spain.
Galisteo-González
F
F
Hidalgo-Alvarez
R
R
D000327:Adsorption; D002097:C-Reactive Protein / Q000737:chemistry / Q000276:immunology; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry / Q000276:immunology*; D007841:Latex Fixation Tests; D008027:Light; D008863:Microspheres; D011137:Polystyrenes / Q000737:chemistry; D012542:Scattering, Radiation; D012967:Sodium Dodecyl Sulfate; D013997:Time Factors
D007140:Immunoglobulin Fab Fragments; D011137:Polystyrenes; D012967:Sodium Dodecyl Sulfate; D002097:C-Reactive Protein