Nucleic acid procedure

No single UHS protein component has been isolated as yet, but sequence data has been obtained using nucleic acid procedures [231], which indicates that UHS proteins are encoded by a separate set of genes. UHS proteins have been identified in sheep, mouse, and human hair but isolation of homogeneous components have been restricted by the extensive heterogeneity and apparent continuous distribution of components [239]. It is of interest that production of UHS proteins was stimulated in regrowth wool after sheep were administered an epidermal growth factor or cyclophosphamide [225,237]. 

GENETICENGINEERING - PROCEDURES] (Vol 12) -binding to nucleic acids pUCLEIC ACIDS] (Vol 17)... 

Microbiological procedures which exploit the ability of bacteria and photosynthetic algae to incorporate exogenous labeled precursors such as 14CO2, SO%, and 32pQ3- [ can be used to label complex molecules in cells such as proteins (qv) and nucleic acids (qv), which are then processed to give labeled constituents such as uniformly labeled C-amino acids, C-nucleotides, C-fipids, LS-amino acids, etc (8). 

Commercial use of cell and tissue culture continues to expand. Improvement of organisms through recombinant nucleic acid techniques has become commonplace. Formerly, a few laboratories were well ahead of most others, but now the methods have been perfected for routine use. Another technique that is widely practiced is culturing of cells that excrete high concentrations of just one antibody protein. The specificity of antibodies and antigens is exploited in medical testing procedures using these pure monoclonal antibodies. 

Montgomery et al. in Synthetic Procedures in Nucleic Acid Chemistry (Zorbach and Tipson eds) Wiley ... 

Crystallisation. The ultimate in purification of proteins or nucleic acids is crystallisation. This involves very specialised procedures and techniques and is best left to the experts in the field of X-ray crystallography who provide a complete picture of the structure of these large molecules. [A. Ducruix and R. Gieg6 eds. Crystallisation of Nucleic Acids and Proteins A Practical Approach, 2nd Edition, 2000,... 

The remainder of this chapter focuses on practical aspects of the preparation and implementation of atomistically based computations of nucleic acids. A flow diagram of the steps involved in system preparation and the performance of MD studies of nucleic acids is presented in Figure 1. Additional details on many of the procedures described here may be found in books by Allen and Tildesly [123] and Frenkel and Smit [124]. 

Taguchi H, Yokoi T, Tsukatani M, Okada Y (1995) Tetrahedron 27 7361 Vekemans J, Pollers-Wieers C, Hoornaert G (1983) J Heterocyclic Chem 20 919 Tutonda M, Vanderzande D, Hendrickx M, Hoornaert G (1990) Tetrahedron 46 5715 Deceuninck JA, Verschave P, Buffel DK, Tutonda M, Hoornaert G (1991) In Townsend LB, Stuart Tipson R (eds) Nucleic acid chemistry, improved and new synthetic procedures, methods and techniques. Wiley, New York, p 144 Buysens KJ, Vandenberghe DM, Toppet SM, Hoornaert GJ (1996) J Chem Soc Perkin Trans 1 231... 

The theory and application of this fluorescence method have been discussed in detail by LePecq and others (3,8). The assay requires that there is sufficient ionic strength to minimize ionic binding (e.g., O.IM sodium chloride), that the pH is 4-10, that no heavy metals are present, that the fluorescence is not enhanced on binding to other excipients (e.g., proteins) and that at least portions of the nucleic acids are not complexed. These requirements can usually he met when dealing with recombinant products in some cases the samples must he manipulated to create the appropriate conditions. In the intercalative method of dye binding, proteins rarely interfere with the assay, and procedures have been developed to remove the few interferences they may cause (e.g., the use of heparin or enzymatic digestion of the protein 9). 

A typical procedure is shown in Figure 2. Other dyes besides ethidium can be used, although ethidium has an advantage in that its excitation emission bands are well removed from any protein absorbances. A standard curve can be constructed for the nucleic acid of concern and the limits of detection established. In Step 3, proteolytic enzymes may be substituted for heparin, or the step may be bypassed in the case of proteins which do not interfere. After measurement of the unknown sample the nucleic acid concentration may be simply calculated or read from the standard curve. 

Figure 2. Analytical procedure used for determining concentration of nucleic acids from fluorescence.

All of the hybridization procedures discussed in this section depend on the specific base-pairing properties of complementary nucleic acid strands described above. Perfect matches hybridize readily and withstand high temperatures in the hybridization and washing reac-... 

Viruses are infectious particles formed by nucleic acid, proteins, and in some cases lipids. As viruses (for example, retro- and adenoviruses) transfer viral genes into cells with high efficiency, modified forms are sometimes used as vectors for gene transfer. However, procedures using virus-based vectors are often significantly more complicated and time-consuming than other transfection methods. In addition, viral vectors are potentially hazardous, and biological safety issues need to be considered carefully. Therefore, techniques that combine... 

Next, four male Sprague-Dawley rats were administered NDPA-[2,3- H] by intraperitoneal injection (12). After 12 hours, the animals were sacrificed, and RNA and DNA were isolated from the combined livers by standard procedures. Following addition of unlabeled, authentic 7-propylguanine and 7-isopropylguanine as markers, the nucleic acids were hydrolyzed in perchloric acid at... 

Collecting samples of ancient nucleic acids is a delicate operation that requires what are basically surgical procedures. It is advantageous, whenever possible, that the samples be collected at excavation sites and precautions taken to ensure that they do not become contaminated with other, particularly more recent, nucleic acids. At high temperatures and humidity, nucleic acids decay quickly. Well-preserved ancient nucleic acids can, therefore, be expected in sites where low temperatures and a dry environment prevail, as, for example, in cold, desert areas of the world. Once collected, the samples need to be isolated from any other remaining materials until they can be amplified by PCR and their chemical composition and structure can then be studied. 

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