Development of an Ultra-sensitive Chemiluminescence Enzyme Immunoassay for the Determination of Diethylstilbestrol in Seafood

Simultaneous Detection of VEGF and CEA by Time-Resolved Chemiluminescence Enzyme-Linked Aptamer Assay

BACKGROUND

As two important tumor markers, vascular endothelial growth factor (VEGF) and carcinoembryonic antigen (CEA) have a great value for clinical application in the early diagnosis of cancer. Due to the complex composition of biological samples, the results from combined detection of CEA and VEGF are often taken as a comprehensive indicator in order to make an accurate judgment on a disease. However, most of the current methods can only be used to detect the content of one biomarker. Therefore, it is necessary to explore a simple, rapid, low-cost, and highly sensitive method for the simultaneous detection of CEA and VEGF.

METHODS

Based on specific aptamers and magnetic separation, a time-resolved chemiluminescence enzyme-linked aptamer assay was developed for the simultaneous detections of CEA and VEGF in serum samples.

RESULTS

Under the optimal conditions, the linear range of the calibration curve for VEGF was from 0.5 to 80 ng mL-1, and the limit of detection was 0.1 ng mL-1. The linear range of the calibration curve for CEA was 0.5 to 160 ng mL-1, and the limit of detection was 0.1 ng mL-1. The established method was applied to detect VEGF and CEA in serum samples. The results were consistent with those of commercial kits.

CONCLUSION

The method has high sensitivity and can quickly obtain accurate results, which could greatly improve the measurement efficiency, reduce the cost, and also reduce the volume of sample consumed. It can be seen that the method established in this study has important application value and broad application prospect in clinical diagnosis.

Hormones and Hormonal Anabolics: Residues in Animal Source Food, Potential Public Health Impacts, and Methods of Analysis

The demand for nutritious food, especially food of animal origin, is globally increasing due to escalating population growth and a dietary shift to animal source food. In order to fulfill the requirements, producers are using veterinary drugs such as hormones and hormone-like anabolic agents. Hormones such as steroidal (estrogens, gestagens, and androgens), nonsteroidal, semisynthetic, and synthetic or designer drugs are all growth-promoting and body-partitioning agents. Hence, in food animal production practice, farm owners use these chemicals to improve body weight gain, increase feed conversion efficiency, and productivity. However, the use of these hormones and hormonal growth-promoting agents eventually ends up with the occurrence of residues in the animal-originated food. The incidence of hormone residues in such types of food and food products beyond the tolerance acts as a risk factor for the occurrence of potential public health problems. Currently, different international and national regulatory bodies have placed requirements and legislative frameworks, which enable them to implement residue monitoring test endeavors that safeguard the public and facilitate the trading activity. To make the tests on the animal-origin food matrix, there are different sample extraction techniques such as accelerated solvent extraction, supercritical fluid extraction, solid phase extraction, solid-phase microextraction, and hollow-fiber liquid-phase microextraction. After sample preparation steps, the analytes of interest can be assayed by screening and confirmatory methods of analysis. For screening, immunological tests such as ELISA and radioimmunoassay are used. Detection and determination of the specific residues will be done by chromatographic or instrumental analysis. Mainly, among high-performance liquid chromatography, liquid chromatography with mass spectrometry (LC-MS, LC-MS/MS), and gas chromatography with mass spectrometry (GC-MS and GC-MS/MS) methods, LC-MS/MS is being preferred because of easier sample preparation without a derivatization step and high detection and quantification capacity.