many modern analytical methods deal with the trace-level determination of compounds of interest in highly complex environmental samples by means of chromatographic techniques. the introduction of a “clean” sample into an analytical instrument can make analyses easier and prolongs the equipment life. the use of solid-phase extraction (spe) has grown and is a fertile technique of sample preparati...

in this article we review the application and procedures involved in scanning electron microscope (sem) to observe biological and live tissues through using sem at high resolution. we discuss practical methods for optimizing tissue preservation to achieve the two principal goals of biological specimen preparation: (a) preserving biological structures as close to their living configuration as po...