Development of a highly sensitive and selective microplate chemiluminescence enzyme immunoassay for the determination of free thyroxine in human serum

Abstract

A microplate chemiluminescence enzyme immunoassay (CLEIA) with high sensitivity, selectivity and reproducibility was developed for the determination of free thyroxine (FT4) in human serum. A competitive assay has been utilized with horseradish peroxidase (HRP) labeled thyroxine analog in the chemiluminescence (CL) detection. The CL signal produced by the emission of photons from luminol was directly proportional to the amount of analyte. The linear range was 0.45-7.5 ng dL -1 and the detection limit was 0.09 ng dL -1 . Experimental conditions, such as temperature, pH, incubation time, titration level and other relevant variables upon the CL signal have been examined and optimized. A coefficient of variance of less than 16% was obtained for intra-and inter-assay precision. The present method has been successfully applied to the analysis of FT4 in human serum. The positive and negative coincidence ratios are satisfactory. Good correlations were obtained between the results by the proposed method and radioimmunoassay (RIA), as well as a Bayer ACS-180SE detection system.

Surgical Management of Hyperthyroidism

“…TSH levels are measured using immunoradiometric and chemiluminescent methods which have a high sensitivity (100%) and specificity (99.1%) [30,31]. When an abnormally low TSH is detected, free Thyroxine (T4) and free Tri-iodothyronine (T3) levels are measured to determine the degree of hyperthyroidism.…”

Technological Development of Antibody Immobilization for Optical Immunoassays: Progress and Prospects

“…Immunoassays are based on the highly specific molecular recognition of antibodies and antigens, which facilitates the sensitive detection of biomolecules such as proteins (Dipti et al, 2012;Kim et al, 2012;Lin et al, 2012;Maple et al, 2012), hormones (Borque et al, 2011;Islam et al, 2011;Troutt et al, 2011;Wang et al, 2007), and drugs, as well as microorganisms (Sandhu et al, 2012). Immunoassays have developed significantly in recent years due to improvements in their specificity, analytical time, and practicability, which can be attributed to the elimination of complex separation and extraction steps.…”

Preparation of an Acridinium Ester-Labeled Antibody and Its Application in GoldMag Nanoparticle-Based, Ultrasensitive Chemiluminescence Immunoassay for the Detection of Human Epididymis Protein 4

“…Lumimol and horseradish peroxidase (HRP) are most widely used as the CL label and catalyst, respectively [ 8 , 9 ]. In the majority of sandwich-type methods, a microplate is always used as an immobilization support [ 10 ]. Based on these, many of the classical biomarkers related to diseases in human blood have been detected accurately [ 11 , 12 , 13 ], which have greatly promoted the development of clinical diagnostic studies.…”