Lanthanide-based time-resolved luminescence immunoassays

The sensitive and specific detection of analytes such as proteins in biological samples is critical for a variety of applications, for example disease diagnosis. In immunoassays a signal in response to the concentration of analyte present is generated by use of antibodies labeled with radioisotopes, luminophores, or enzymes. All immunoassays suffer to some extent from the problem of the background signal observed in the absence of analyte, which limits the sensitivity and dynamic range that can be achieved. This is especially the case for homogeneous immunoassays and surface measurements on tissue sections and membranes, which typically have a high background because of sample autofluorescence. One way of minimizing background in immunoassays involves the use of lanthanide chelate labels. Luminescent lanthanide complexes have exceedingly long-lived luminescence in comparison with conventional fluorophores, enabling the short-lived background interferences to be removed via time-gated acquisition and delivering greater assay sensitivity and a broader dynamic range. This review highlights the potential of using lanthanide luminescence to design sensitive and specific immunoassays. Techniques for labeling biomolecules with lanthanide chelate tags are discussed, with aspects of chelate design. Microtitre plate-based heterogeneous and homogeneous assays are reviewed and compared in terms of sensitivity, dynamic range, and convenience. The great potential of surface-based time-resolved imaging techniques for biomolecules on gels, membranes, and tissue sections using lanthanide tracers in proteomics applications is also emphasized

Receptivity to Protective Garments among the Elderly

Hip fractures among elders resulting from falls are a growing concern as the proportion of elders increases and health care costs mount. A recent innovation is the development of an undergarment worn to protect against hip injuries. This study attempted to determine whether a community population of elders would be receptive to wearing such a garment and the characteristics of those who would and would not be receptive. It was assumed that receptivity can be predicted by variables that have been shown to relate to risks of falling. Predictor characteristics represent three domains: demographic/predisposition, health/mobility, and social support. A logistic regression procedure was employed to determine the probability and odds of receptivity among elders given a profile of specific characteristics. Results were interpreted with reference to past research on risks of falling.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66692/2/10.1177_089826439700900305.pd