NEW CHALLENGES FOR ICP-MS INSTRUMENTATION AND DATA ACQUISITION. SOLVING PROBLEMS OF REAL LIFE BIOLOGY.

摘要

Many contemporary fields of biotechnology have greatly benefited from the introduction of ICP-MS based methods. Among these is the traditional elemental analysis of proteins, cell cultures, tissues, and body fluids. The recent development of methods for sulfur and phosphorus determination has allowed phosphoproteins to be accurately quantitated through ICP-MS analysis. New methods have also demonstrated that elemental tags for biomolecules, in conjunction with ICP-MS, offer many attractive features in comparison with traditional fluorescent or radioactive detection and quantitative systems. Such interest is based on certain qualities of ICP-MS as a high sensitivity detector. This technique requires novel sample preparation strategies as discussed in Quinn et al.. To summarize some advantages and expectations; ICP-MS as a method of detection offers the inherent ability to provide: i) absolute quantitation; ii) high sensitivity and low detection limits proportional to the number of atoms in sample (or similar atoms in the tag); and iii) linearity of response. ICP-MS based analytical methods created specifically for biological challenges take advantage of well-established analytical strategies. Using ICP-MS detection, element-tagged biomolecule detection is not affected by biological impurities, which have less impact since they generally do not contain the target elements and allows relative insensitivity to concomitant organic or metallic species. ICP-MS detection allows for multiplexing in which multiple differently tagged molecules in one sample are analyzed simultaneously. There exist possibilities of a "simple" analysis in which approx60 elements could be multiplexed via approx240 isotopes. An immunoassay method designed to quantitate a particular antigen coupled to the ICP-MS relies on element-tagged antibodies and equivalent sensitivity to all similarly tagged antigen/antibody complexes. Where the method includes immediate acidification of the biological sample, the assay state can be "frozen" at any moment and safety and storage/transportation concerns can be easily addressed. We will demonstrate some of these advantages in the following sections.