We report on laser-induced breakdown spectroscopy (LIBS) of whole blood and other organic fluids. LIBS spectra, in the region 200-970 nm, are measured by recording the radiation emitted by the samples following their ablation in a helium environment. We show that these spectra, although very complex, reveal the presence of elements such as nitrogen, hydrogen, oxygen and carbon and that of important metallic elements such as iron, magnesium, calcium, potassium, and sodium. We compare the measured LIBS spectra of whole blood to that of pure carbon and pure iron and find that in the 200-300 nm region. Nearly 90% of the peaks can be assigned to only these two elements. We also report on similar studies of methanol, ethanol, isopropanol and water solutions of protein molecules of interest to cancer research. We show that using simple numerical algorithms, it is possible to distinguish between complex organic compounds that have nearly the same chemical composition.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.