Interference neutralizing antibody assays

Quantification of an analyte in an agricultural sample relates to both the assay procedure and the sample preparation procedure. Conventional analyses frequently focus on total residues and may employ relatively harsh extraction procedures to remove bound materials from the soil or crop sample. The biological nature of antibodies requires that most immunoassays be run in aqueous systems at a pH near neutrality. If total residues are to be measured and extraction requires the use of organic solvents, strong acids, or strong bases the extracted materials must be dispersed in an aqueous medium prior to using an immunoassay. Moderate levels of methanol (<10i) and other water miscible solvents do not interfere with most immunoassays. 

Sample preparation. Although there is not a gold standard for sample preparation and target extraction for analysis by immunoassay, most use saline buffers (e.g., phosphate-buffered saline, Tris saline buffer, high-salt buffers) at neutral pH to prevent interference and inhibition of antigen-antibody binding. Similarly, there is no standardized extraction method for DNA-based assays, and extraction efficiency is matrix dependent. However, unlike immunoassays, DNA-based assays will withstand the use of harsh conditions. 

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