Specimen solid tissue

The sample materials from which proteins for proteomics studies may be extracted include fresh or snap-frozen cells from varied sources such as biological fluids, (serum, urine, plasma) and solid tissues such as biopsy specimens. Moreover, proteins isolated from ethanol-fixed paraffin-embedded tissues can be utilized for MS analysis.2 Protocols for the identification of proteins from formalin-fixed paraffin-embedded (FFPE) tissues have been recently developed.3 4 FFPE materials are the most common forms of biopsy archives utilized worldwide, and represent an important advancement for the large-scale interrogation of proteins in archival patient-derived materials. Finally, laser capture microdissected tissues have been successfully used for MS analysis.45... 

Many errors can occur during the collection, processing, and transport of biological specimens. Minimizing these errors win result in more reliable information for use by healthcare professionals. Examples of biological specimens that are analyzed in clinical laboratories include whole blood serum plasma urine feces saliva spinal, synovial, amniotic, pleural, pericardial, and ascitic fluids and various types of solid tissue. The National Committee for CMnical Laboratory Standards (NCCLS) has published several procedures for collecting many of these specimens under standardized conditio ns.In addition, the NCCLS has published documents related to sample collection and analysis for specialized tests, such as sweat chloride (see also Chapter 27). 

Typical examples of solid samples include large particulates, such as those found in ores smaller particulates, such as soils and sediments tablets, pellets, and capsules used in dispensing pharmaceutical products and animal feeds sheet materials, such as polymers and rolled metals and tissue samples from biological specimens. 

A recent innovation in electron microscopy is environmental SEM, which allows samples to be studied at pressures and humidities that approach ambient conditions. To achieve this, several stages of differential pumping between the electron gun and the sample are used, and the sample itself is placed in a vacuum of a few hundred Pascals. Environmental SEM enables many materials to be examined without pretreatment, unlike conventional SEM, in which specimens must be solid, dry and usually electrically conductive. This now makes possible studies of the natural, unadulterated surfaces of specimens such as polymers, biological tissues and cells, food and drugs and forensic materials. 

Preparation of specimens. The mixture to be separated is applied to the paper as a solution. The solution should be 0.5% of which 10 pi are applied to the paper. The precise amount and concentration will depend on the complexity of the sample mixture and the sensitivity of the detection system. The nature of the solvent is immaterial, as long as it will evaporate completely without leaving a residue, and without attacking the paper. Solid samples, such as oils, or biological cell or tissue material, are macerated with the solvent, or submitted to some standard extraction procedure, such as Soxhlet. Many important samples, such as urine or other biological fluids, are already in an aqueous medium. In other cases water is used as the solvent when the substances are soluble in it. 

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