Labeling immunoassays

Certain drugs such as chloramphenicol require additional tests for their detection and quantification in meat tissues. The Competitive Enzyme Labeled Immunoassay for Chloramphenicol (CELIA) was developed and is used by FSIS laboratories to detect and quantify this drug in the meat supply chloramphenicol is not approved for use in food animals. CELIA detects 5 ppb chloramphenicol in tissue extracts. 

For high sensitivity immunoassay, the detection limit of the label must be in the sub-picomolar range. It is possible to have good sensitivity when two or three labels are used in assays but sensitivity is compromised when four labels are involved. Quadruple-label immunoassays of four analytes have been made [190] as shown in Fig. 12.35. 

Fig. 12.35. Quadruple-label immunoassays of four analytes (thyroid stimulating hormone, 17a-hydroxyprogesterone, immunoreactive trypsin and creatine kinase) in a single assay cuvette with...

Major labelled immunoassays include RIA, ElA, fluoroimmunoassay, chemiluminescence immunoassay, protein microarrays, and simplified immunoassay. 

Both competitive and noncompetitive methods have been incorporated into homogeneous enzyme-labeled immunoassay kits that ultimately relate enzyme activity to analyte concentration.22 The competitive-binding assays are called enzyme-multiplied immunoassay technique (EMIT), substrate-labeled fluorescein immunoassay (SLFIA), apoenzyme reactivation immunoassay (ARIS), and cloned enzyme donor immunoassay (CEDIA), while a noncompetitive method is called enzyme inhibitory homogeneous immunoassay (EIHIA). 

A10. Asayama, K., and Burr, I. M., Rat superoxide dismutases—Purification, labeling, immunoassay, and tissue concentration. J. Biol. Chem. 260, 2212-2217 (1985). 

T21. Tsuji, A., Maeda, M., Arakawa, H., Matsuoka, K., Kato, N., Naruse, H., and Irie, M., Enzyme immunoassay of hormones and drugs by using fluorescence and chemiluminescence reaction. In International Symposium on Enzyme-Labeled Immunoassay of Hormone and Drugs (S. B. Pale, ed.), pp. 327-329. de Gruyter, Berlin, 1978. 

The technology can be applied for double- triple- and quadruple-label immunoassays, cytotoxicity and oligonucleotide based genetic screening assays (16,18,25,24). 

Zhu L, Leinonen J, Zhang WM, Fiime P, Stenman UH (2003) Dual-label immunoassay for simultaneous measurement of prostate-specific antigen (PSA)-alphal-antichymotrypsin complex together with free or total PSA. Clin Chem 49 97-103... 

Evaluation and Comparison of Enzyme-immunoassay, Gas-Liquid Chromatography and High-Pressure Liquid Chromatography for the Monitoring of Antiepileptic Drugs in Serum Enzyme Labelled Immunoassay Horm. Drugs, Proc. Int. Symp. 1978 405-418 CA 91 204051f... 

S. Matern, K. Tietjen, H. Matern and W. Gerok, Enzyme labelled immunoassay for a bile acid in human serum, in "Enzyme labelled immunoassay of hormones and drugs , S.B. Pal. ed., Walter De Gruyter e Co., Berlin, 457 (1978). 

---