Identification, location and analysis of contamination problems associated with cell/tissue preparation, stimulation and measurement techniques.

Any time a cell suspension or tissue sample is handled, chemically treated and prepared or measured with electrical or electrochemical probes, some level of contamination will occur. Often, the level and type of contamination can lead to serious misinterpretation of experimental results. A number of specific contamination problems have been consistently observed with certain preparation, stimulation and measurement techniques utilized in cell biology, histology, microbiology and pharmacology. Four of the more serious problems that can occur are as follows: 1) contamination from media constituents; 2) contamination of cell suspensions and tissue from constituents and impurities in glassware; 3) fungal contamination of cell and tissue samples from glutaraldehyde fixatives and 4) contamination of cell suspensions and tissues from metal ions that have dissociated from electrodes and probes. A scanning electron microscope/energy dispersive x-ray (SEM/EDX) system can provide the resolution, sensitivity and analytical capability to detect these contaminants in a variety of locations, identify them and determine their origin. Thus, erroneous conclusions from data that have been affected by various contaminants can be minimized or prevented if the problems are identified and located.