Technical and Practical Considerations

In performing electrophoretic separations, a number of technical and practical aspects need to be considered as they affect the process. 

To achieve a proper balance between sensitivity and resolution, the amount of serum protein that is applied to an electrophoretic support must be optimum. Albumin is about 10 times more concentrated in serum than the smallest fraction, the ai-globulins. Therefore the amount of serum applied should prevent overloading with albumin but still be adequate to quantify arglobulin. For the separation of serum proteins using polyacrylamide gel electrophoresis (PAGE), 3(lL of serum containing approximately 210 pg of total 

Discontinuities in sample application may be caused by dirty applicators in cellulose acetate or inclusion of an air bubble in AGE. In practice, caution must be used in cleaning applicators because they are easily bent. Twin-wire applicators are best cleaned merely by agitating in water followed by gently pressing the applicators against absorbent paper. It is inadvisable to clean wires by manual wiping. The pipette tip should be checked for air bubbles before application of the sample to the agarose gel template. 

Atypical bands in an isoenzyme pattern maybe the result of binding by an immunoglobulin (a macroenzyme). 

Because buffers used in electrophoresis are good culture media for the growth of microorganisms, they should be refi igerated when not m use. Moreover, a cold buffer is preferred in an electrophoretic run, because it improves resolution and decreases evaporation fi om the electrophoretic support. Buffer used in a small-volume apparatus should be discarded after each run because of pH changes resulting from the electrolysis of water that accompany electrophoresis. If volumes used are larger than 100 mL, buffer from both reservoirs may be combined, mixed, and reused up to four times. 

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Supercritical fluid extraction (SFE) has become more commonplace in analytical laboratories as an alternative technique to more traditional, manual techniques. While SFE is a relatively new technology to the analytical laboratory, feasibility in terms of affording acceptable levels of recovery (accuracy) has been demonstrated for a real diversity of samples by many researchers. Other workers have evaluated many of the usual technical and practical considerations applied in developing a new technique and the resulting conclusions have not indicated any insurmountable issues associated with those considerations which would preclude the continued development of SFE as a powerful tool for the analytical chemist. One major consideration which has received somewhat minimal attention thus far is that of the robustness of the technique. 

In this section, instrumentation, general electrophoretic operations, technical and practical considerations, and types of conventional electrophoresis are discussed. 

It is also useful to assure that internal (company specific) practices are adhered to in method development by making these considerations part of the MDRD. Based on the voice of the customer surveys, several technical and practical method attributes have been identified within our organization. 

A recent study of para-hydroxybenzoate hydroxylase (PHBH) by Bidder et al. [49,50] provides an interesting example of the validation of QM/MM calculations on the enzyme mechanism by comparison with experimental data. The correlation found between calculated activation barriers and the logarithm of experimental rate constants for a series of alternative substrates also provides support for the proposed mechanism hydroxylation of hydroxylation. These studies are a good example of QM/MM reaction pathway calculations for an enzyme, including technical aspects of system set-up and practical considerations, and so will be outlined here in some detail. 

As plants age there is a need for increased maintenance on the process equipment to ensure continued operability. To ensure safe and reliable operation, the maintenance practices used must follow suggested vendor recommendations or be defined internally to address technical and safety considerations. The continued operability of chemical agent stockpile incineration facilities is dependent in part on the effectiveness of the maintenance systems to proactively address obsolescence in their procedures and practices and to modify systems as required to process severely degraded stockpile items. 

Tests of high-capacity stationary cells with auxiliary catalytic electrodes were conducted at a number of battery plants, but on grounds of certain technical and economical considerations, this method of recombination of hydrogen and oxygen has not found wide practical application in the battery industry. 

The scientific and technical corrosion literature has descriptions and lists of numerous chemical compounds that exhibit inhibiting properties. Of these only a very few are ever actually used in practical systems. This is partly due to the fact that in practice the desirable properties of an inhibitor usually extend beyond those simply relating to metal protection. Thus cost, toxicity, availability, etc. are of considerable importance as well as other more technical aspects (see Principles). Also, as in many other fields of scientific development, there is often a considerable time lag between laboratory development and practical application. In the field of inhibition the most notable example of this gap between discovery and application is the case of sodium nitrite. Originally reported in 1899 to have inhibitive properties, it remained effectively unnoticed until the 1940s it is now one of the most widely employed inhibitors. 

Practical consideration of the ability to produce and deploy reactors in the numbers necessary dictates that currently successful systems be sustained and their installation encouraged by governments until and unless advanced systems are fully available and acceptable technically, economically, and industrially. 

A simple reminder or jogger that an operation is vulnerable or that an existing standard or practice is critical. The effectiveness of such a reminder depends on the background of the reader. For those with considerable technical and operations experience, lessons learned will drive a quest for more information. Ultimately, this... 

Construction of Buildings and Installations for Explosives Propellant plants. Technical safety considerations and practical experience in the planning and constructing of explosives propellant plants are aspects of the subject discussed by Banik (Ref 1), See also Ref 2 Refs 1)E.Banik, Explosivst 1956, 130 34 155-58 2)Anon, "AMC Safety Manual" (1964), Sect 5-1, 5-10, 5-19, 18-3 18-4... 

The Institute also established an informal criminalistics advisory board which offered considerable assistance in the review and evaluation of concept papers and proposals submitted for funding. This panel composed of six leading criminalists, researchers and educators, served as an independent source of technical expertise and practical experience in the field of criminalistics. In addition to this group, a panel of forensic scientists from several federal law enforcement agencies was formed and has met periodically to discuss important issues in the administration of research projects. 

Construction of Buildings ond Installations for Explosives Propellant pSunf Technical safety considerations and practical experience m the planning and constructing of explosives propellant plants are aspects of the subject... 

In discussing the postulated murder of the Jews, the historians of the status quo identify the technical and organizational origins of this mass murder as to be found in the program of euthanasia which was enforced as of the beginning of the war - the killing of so-called life not worthy of life , in other words, mentally and/or physically severely disabled people. The reason for this assumption is the considerable overlap, i.e., continuity of staff in both areas.88 However, it seems to me a very dubious practice to attempt to construe this continuity as evidence for the mass murder, since it may very well mean only that the leadership had wished to retain staff which had previously proven loyal in one socially extremely controversial operation, for a subsequent, no less controversial purpose. And whether this controversial purpose was the resettlement, ghettoization, or mass murder of the Jews, is still an open question. 

For most new biotechnological products, processes and analytical methods have to be newly established. This represents a major and costly part of product development. In newly founded biotechnology firms pertinent technical experience and practical knowledge about the application of regulatory requirements is usually missing and must be developed. Early information and consideration of these aspects may considerably shorten this learning process. 

Technical and other practical factors also merit consideration. Are there indeed technical difficulties in the manufacture of a bulk drug that would render marketing of the eutomer cost-prohibitive Accumulation of relevant data for each stereoisomer is a time-consuming process. Are these delays justifiable therapeutically When an IND is submitted for a race-mate, there may be limited or negligible safety and/or pharmacokinetic data on the individual enantiomers. Should this delay initiation of phase I clinical trials ... 

These inks contain high concentrations of low-boiling solvents, and the usual practice is to dilute them further in the press room. The large volume of solvents emitted makes incineration impractical, but these solvents may be absorbed on activated charcoal, and removed l steam distillation when the charcoal is saturated. The recovered solvents may be re-used or sold however, it may be impractical to fractionate some recovered solvent blend that boil in the same temperature range, which lessens their value considerably. Therefore, although this approach is also technically and economically feasible, the difficulty in procuring the solvents used for dilution may restrict the continued use of these solvent-based inks and, hence, the adoption of solvent recovery approach. 

There are thus three fixed points to consider in the testing of fireclays or for that matter in the examination of refractories in general, viz., the vitrification temperature at which the mass becomes dense and practically impervious, the point at which it becomes overfired and vesicular and the softening temperature. The difference between the vitrification and overfiring temperature constitutes the vitrification range which is of considerable technical importance from the manufacturing standpoint. 

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