Comparison of ELISA and DNA Lateral Flow Assays for Detection of Pork, Horse, Beef, Chicken, Turkey, and Goat Contamination in Meat Products.

Background: Concerns about the contamination of meat products with undeclared meats and new regulations for the declaration of meat adulterants have established the need for a sensitive test to detect meat adulteration. To address this need, Microbiologique, Inc. has developed ELISA assays that can detect the presence of pork, horse, beef, chicken, turkey, and goat meat adulterants to 0.1% (w/w) and a deoxyribonucleic acid (DNA) lateral flow assay for pork, horse, beef, chicken, turkey, goat, and lamb adulterants to 0.1% (w/w). Objective: We compared the results of the DNA lateral flow assay to the ELISA assays. Methods: ELISA and DNA lateral flow assays were performed on the same spiked meat samples, prepared meats, and pet foods. Results: Both the DNA lateral flow and the ELISA assays were sensitive to 0.1% meat adulterant, and the agreement between the DNA lateral flow and ELISA assays for spiked samples, prepared meat, and pet foods was 100%. Conclusions: Based on the 100% concordance between the two assay formats, the choice between the two is dependent on whether quantitation is desired, which assay is more familiar to the particular laboratory, availability of the required equipment, and time restrictions. Highlights: The ELISA assays are less time consuming, taking about 1.5 h, compared with about 2.5 h for the DNA lateral flow assay. Because the DNA lateral flow test detects seven species in one test, it can be more cost effective when the potential adulterant is not known, while the ELISA may be better for quantification.

Circulating bone marrow stem/progenitor cells in vascular atherogenesis and in the noninvasive diagnosis of coronary stenosis.

Using autopsy specimens and clonal technique, the authors showed that hematopoietic and stromal stem colony-forming units are present in human atheromatous vascular intima. Stromal colony-forming units were also detected in the mononuclear fraction of the blood of patients with hyperlipidemia and coronary stenosis, and were not found in the peripheral blood of normolipidemic volunteers. Using flow cytometry, the absence of stromal circulating colony-forming units in healthy volunteers and their presence in coronary patients was confirmed. It was thought that the presence of circulating stromal precursors with a certain phenotype and variations in their level in blood could serve as an informative noninvasive indicator of coronary stenosis.

Circulating stromal osteonectin-positive progenitor cells and stenotic coronary atherosclerosis.

The level of circulating stromal progenitor cells carrying osteonectin (ON), a marker of osteogenic differentiation, was evaluated by flow cytometry in blood of patients with coronary artery disease (CAD). Ninety-nine patients with CAD were included into the study. Coronary angiography of all patients showed critical stenosis of at least 2 coronary arteries or their major branches. The control groups included 8 patients without CAD and 19 healthy volunteers. In control patients, no lesions of the coronary bed were found by angiography. The absence of CAD in the volunteers was confirmed by bicycle stress test. The content of ON-positive cells in blood was examined in various populations of lymphocyte-like cells. It was found that the number of ON+ lymphocyte-like cells with CD41 positivity in blood of patients without coronary stenosis (0.27%+/-0.11%, mean+/-SD) did not differ significantly from corresponding value in healthy volunteers (0.26%+/-0.07%, p=0.94). In CAD patients, the percent of these ON+ cells was 1.01%+/-0.49% and was significantly higher than in blood of healthy volunteers (p<0.0001) and patients without CAD (p<0.0001). High content of ON+ lymphocyte-like cells with CD41 positivity in blood may serve as noninvasive marker of arterial atherosclerosis.