To test the hypothesis that broad spectrum antibodies may be developed as biomarkers useful in detecting the consequence of combined environmental stresses in a wide variety of tissues and organisms, a stretch of 16 amino acids, TVPAYFNDSQRQATKDA, a well-conserved portion of heat shock 70 proteins, was identified, against which specific antibodies could be designed. This stretch of peptide was synthetically prepared and used as a hapten for antibody preparation by coupling to keyhole lympet hemocyanin, injecting into a rabbit, collecting its blood, and purifying an IgG-rich fraction. The resulting polyclonal antibody was found to react with many heatshock protein (HSP) 70s in every species tested so far, including two species of fish and one amphibian, two arthropod, and one plant species. To relate the reactivity of this antibody preparation to heat shock proteins known to be induced by environmental stress, a Western blot assay method was used to study several organisms under unstressed or stressed conditions. Invariably, heat treatment caused a rise in the titer or HSP70 and/or glucose-regulated proteins. In addition, in some species chemical stresses were also found to be manifested in the form of an increased titer of these proteins.