Methods for the detection and measurement of tagged (labeled) biologically
active materials in a sample are described. The tagged biologically
active materials are detected using an atomic mass or optical
spectrometer having a source of atoms or atomic ions. Element-labeled
biologically active materials, comprising antibodies, antibody Fab'
fragments, antigens, aptamers, protein complexes, growth factors,
hormones, receptors and other biologically active materials attached to a
stable elemental tag, can be used in specific binding assays and measured
by elemental spectroscopic detection. Also described are methods for the
determination of metals in samples of interest using specific antibodies
to isolate the target metals and elemental spectroscopy for detection and
quantitation. Kits are provided comprising reagents to detect and measure
labeled biologically active materials or labeled competition analytes.