Serum separation techniques

With the study of the migration of hydrogenium ions (H ) in a phenolphthalein gel by Lodge in 1886 and the description of the migration of ions in saline solutions by Kohlraush in 1897, a basis was set for the development of a new separation technique that we know today as electrophoresis. Indeed, several authors applied the concepts introduced by Lodge and Kohlraush in their methods and when Arne Tiselius reported the separation of different serum proteins in 1937, the approach called electrophoresis was recognized as a potential analytical technique. Tiselius received the Nobel Prize in Chemistry for the introduction of the method called moving boundary electrophoresis. ... 

Bdnisch, M.P., Tolkach, A., and Kulozik, U. (2006). Inactivation of an indigenous transglutaminase inhibitor in milk serum by means of UEIT-treatment and membrane separation techniques. Int. Dairy J. 16 (6) 669-678. 

The separation technique can be used in two different ways for the measurements of physico-chemical parameters. In one approach the propenies of the compounds are characterised directly from the chromatographic retention which is determined by the interaction of solutes with the stationary and the mobile phases. This approach can be used for lipophilicity determination, measurements of serum albumin binding and estimating the membrane transport of compounds from their retention on immobilised artificial membrane. 

Enzyme immunoassay and RIA kits for the measurement of sahvary DHEA and DHEA-S are commercially available for research purposes. " Analysis of DHEA by immunoassay usually requires pretreatment of serum samples, because the serum concentration of DHEA is 1000-fold lower than that of DHEA-S. Several extraction and chromatographic procedures have been suggested for this purpose. Celite is the preferred adsorbent, and dichloromethane and ethyl acetate are common choices for extraction solvents. Commercial RIA kits using solid-phase separation techniques and I-... 

Maternal serum specimens can be obtained from nonfasting women by standard phlebotomy techniques. UE3 is the least stable of the four analytes currently used for screening, and consequently, requirements for collection, storage, and shipment are dictated by this analyte. The uEj concentration increases in blood at room temperature and at 4 °C, because the conjugated forms can spontaneously deconjugate to form the parent hormone.Therefore collected blood should be allowed to clot and then serum should be removed promptly. If serum separator tubes are used, specimens should be centrifuged promptly after collection. Shipment of whole blood is not preferred. If whole blood is shipped through the mail, next day delivery is essential. UE3 is stable in serum for up to 7 days at 2 C to 4 C (unpublished data, Foundation for Blood Research, Woman and Infant s Hospital, and ARUP Laboratories). The concentration of UE3 increases when sera have been stored for more than 4 days at room temperature. 

This method is based on the accessibility of the pores in the stationary phase for 99mrpc-iabeled molecules of different molecular sizes. The sample is eluted from a vertical column packed with porous beads of the gel by gravity or low pressure. Smaller Tc species penetrate the pores and are retained on the column, while larger molecules are excluded and are therefore rapidly eluted from the column. This separation technique has particular application for macromolecules, proteins (serum albumin, immunoglobulins [e.g., monoclonal antibodies and their fragments]), but has also been used for separation of small-molecular-weight Tc-diphosphonate complexes. 

Development of electrophoretic protein separation techniques have been paralleled by improvements in protein detection methods. Protein detection in early electrophoretic applications, utilizing electrophoretic separations of solutions or colloidal suspensions from about 1816 to 1937, was limited to direct visualization of proteins coated onto microspheres, or studies of naturally colored proteins such as hemoglobin, myoglobin, or ferritin <1-4). An increase in sensitivity and the ability to detect non-colored proteins was achieved by the use of the specific absorption, by proteins, of ultraviolet light. This detection technique permitted Tiselius,in 1937, to demonstrate the quantitative electrophoretic separation of ovalbumin, serum globulin fractions and Bence Jones proteins (S). Tiselius also employed the shadows, or schlieren, created by the boundaries, due to the different concentrations of proteins in the electrophoretic system to detect protein position and concentration ( ). These detection methods served as the main methods for protein detection in the liquid electrophoresis systems. However,... 

The first application of on-line dialysis to a flow system seems to be that made by Skeggs [ 1 ] in his pioneering work on segmented continuous flow analysis. The first report on using on-line dialysis in a non-segmented flow system was that made by Kadish and Hall [2], whereas Hansen and Ruzicka [3] were the first to report such applications in FIA. Despite its early implementation in HA, apyplications of on-line dialysis in this field have been rather few compared to other separation techniques, and mostly dedicated to the analysis of blood serum. This may be due to the fact that dialysis is a slow separation procedure compared to the speed of most FI procedures, and the dialysis efficiencies are usually quite low. 

In the 50 years since its introduction, the use of GC by the petroleum industry has helped foster many breakthroughs in GC instrumentation. Open-tubular GC columns and the theory that describes them were first introduced by Golay and Ettre in the mid-1950s. The further development of open-tubular capillary columns was done by Desty of British Petroleum, and, with subsequent refinement, this technique is now the standard method for most GC applications. The use of GC for sample analysis was also quickly adopted by the pharmaceutical and food industries and is used for fundamental studies of reaction kinetics and physiochemical measurements. Today the use of GC for the analysis of complex samples such as serum proteins, natural products, essential oils, and environmental samples has become a routine with multidimensional separation techniques and multivariate chemometric analysis providing identificatimi and quantification of trace analytes from complex samples in the sub-ppb range. A GC system usually consists of the following elements (Fig. 1) ... 

Electrophoresis is a separation method based on the differential rate of migration of charged species in an applied dc electric field. This separation technique was first developed by the Swedish chemist Arne Tiselius in the 1930s for the study of serum proteins he was awarded the 1948 Nobel Prize in Chemistry for this work. 

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