Enzyme-linked immunosorbent assay preparation

In each of the assays of potency the amount of the immunoglobulin and the amount of a corresponding standard preparation that are required to neutralize the infectivity or other biological activity of a defined amount of virus or to neutralize a defined amount of a bacterial toxin are determined. The two determined amounts and the assigned unitage of the standard preparation are then used to calculate the potency of the immunoglobulin in International Units (lU). ELISA, enzyme-linked immunosorbent assay. 

The need to understand the fate of pesticides in the environment has necessitated the development of analytical methods for the determination of residues in environmental media. Adoption of methods utilizing instrumentation such as gas chro-matography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), liquid chromatography/tandem mass spectrometry (LC/MS/MS), or enzyme-linked immunosorbent assay (ELISA) has allowed the detection of minute amounts of pesticides and their degradation products in environmental samples. Sample preparation techniques such as solid-phase extraction (SPE), accelerated solvent extraction (ASE), or solid-phase microextraction (SPME) have also been important in the development of more reliable and sensitive analytical methods. 

Immunoaffinity cleanup was first applied in drug residue analysis for the determination of chloramphenicol in swine muscle tissue by LC (113). The lAC column was prepared using monoclonal antibodies originally developed for an enzyme-linked immunosorbent assay (ELISA) method (171) specific for chloramphenicol. Meat samples were extracted with water, and a concentrated phosphate buffer was added to the filtered extracts before immunoaffinity cleanup. A phosphate buffer was used in the washing process, whereas chloramphenicol was eluted from the column with a glycine/sodium chloride solution of pH 2.8. For subsequent LC analysis, this eluate was extracted with ethyl acetate, evaporated, and reconstimted in the mobile phase. The same analytical scheme was later successfully applied for the determination of chloramphenicol in eggs and milk as well (170, 172). 

Mart ianov, A.A., A.V. Zherdev, S.A. Eremin, et al. 2004. Preparation of antibodies and development of enzyme-linked immunosorbent assay for nonylphenol. Int. J. Environ. Anal. Chem. 84 965-978. 

Adrian, J., H. Font, F. Sanchez-Baeza, et al. 2008. Preparation of polyclonal antibodies for the generic determination of sulfonamide antibiotics and development of an enzyme-linked immunosorbent assay (ELISA) for milk analysis. J. Agric. Food Chem. 51 385-394. 

Salvador, J.P., F. Sanchez-Baeza, and M.P Marco 2007. Preparation of antibodies for the designer steroid tetrahydrogestrinone and development of an Enzyme-Linked Immunosorbent Assay for human urine analysis. Anal. Chem. 79 3734—3740. 

Chatterjee, U., Mondal, G., Chakraborti, P., Patra, H. K., and Chatterjee, B. P 2006. Changes in the allergenicity during different preparations of pomfret, hilsa, bhetki and mackerel hsh as illustrated by enzyme-linked immunosorbent assay and immunoblotting. Int Arch Allergy Immunol 141 1-10. 

This chapter describes the procedures that can be used to determine compounds that have antiviral activity against HIV. These include maintenance of lymphoblastoid cell lines, preparation of peripheral blood mononuclear cells (PMMCs), and determination of the infectivity of the HIV stock-supernatant and antiviral assays. The assays described use both acutely and chronically infected cells. Toxicity of compounds is assessed by measuring 14C uptake. These protocols are used for the evaluation of compounds that can be carried out by a single individual in a Category 3 containment laboratory. The number of compounds analyzed would be about 10, which is a convenient number to fill a single 96-well p24 enzyme-linked immunosorbent assay (ELISA) plate. 

Laboratory testing for ricin is limited, especially for inhalational exposures. The two common methods that can detect ricin in blood or other body fluids are the radioimmunoassay and the enzyme-linked immunosorbent assay (ELISA). Because ricin binds quickly and the body metabolizes it efficiently before excretion, the length of time necessary for these tests limits their usefulness for inhalation exposures (35). Besides testing body fluids, the CDC and member LRN state public health laboratories have a time-resolved fluorescence immunoassay that can test preparations of suspected ricin-containing substances and environmental specimens for the presence of ricin (40). 

Accurate measurement of proinsulin has been difhcult for several reasons the blood concentrations are low antibody production is difficult most antisera cross-react with insulin and C-peptide, which are present in much higher concentrations the assays measure intermediate cleavage forms of proinsulin and reference preparations of pure proinsulin are not readily available. However, a more sensitive nonequiUb-rium RIA method for measuring proinsiilin was developed by adsorbing the initial antiserum with biosynthetic human C-peptide coupled to agarose to eliminate cross-reactivity with C-peptide.An enzyme-linked immunosorbent assay (ELISA) has been described that employs an antibody to C-peptide as the coating antibody and antiinsulin antibody for detection. The detection limit is 0.25 pmol/L. ... 

---