Antibodies conjugated with new highly luminescent Eu3+ and Tb3+ chelates as markers for time resolved immunoassays. Application to simultaneous determination of clenbuterol and free cortisol in horse urine.

This research examines the use of luminescent compounds, specifically Eu(3+) and Tb(3+) complexes, conjugated with antibodies for quantitative determination of clenbuterol and hydrocortisone in horse urine. The study demonstrates high sensitivity and has significant implications for controlling illicit drug use in horses.

Research Methodology and Resources

• The experiment hinged around the use of luminescent Eu(3+) and Tb(3+) complexes which were linked, or conjugated, with specific antibodies – specifically, a goat anti-rabbit IgG and a rabbit anti-mouse IgG.
• Theses specific antibodies were then used in a time resolved immunoassay, a biochemical test that measures the presence or concentration of a macromolecule in solutions through the use of an immune reaction.
• This assay was specifically used for the simultaneous quantitative determination of clenbuterol (CL) and hydrocortisone (HC), two substances sometimes improperly used in horse racing to increase performance.

Key Findings

• The research found that these lanthanide chelates (compounds containing a metal ion attached to a certain molecule, in this case the Eu(3+) and Tb(3+) complexes) were both stable and highly luminescent in aqueous solution.
• This luminescence allowed for the detection of clenbuterol and hydrocortisone in horse urine samples at sensitivities of 10 microg L(-1) and 40 microg L(-1), respectively.
• Given the sensitivity of these compounds and their ability to function in a complex matrix like horse urine, this method offers potential for controlling the improper use of these substances in horses.

Implications and Association

• Clenbuterol and hydrocortisone are both substances that can be used to illicitly improve horse performance in racing, leading to unfair competition and potential harm to the horses.
• Therefore, the development of sensitive and accurate detection methods is paramount in controlling this abuse.
• This study shows the potential use of luminescent conjugated antibodies in developing such detection methods, contributing to efforts to maintain ethical and safe practices in the horse racing industry.