Fluorescence nucleic acids purification

In current practice the fluorescence assay is often followed by the use of hybridization techniques when more selectivity is required. We have for instance used the fluorescence techniques to obtain data on the nucleic acid content of malaria vaccine proteins produced in Escherichia coli. The rapid turnaround time of the fluorescence assay is particularly useful during the early stages of purification to determine the optimal process conditions. After the final process has been arrived at and a variety of methods used to assess the nucleic acid content (including the hybridization techniques), the fluorescence method can be developed for routine quality-control purposes. In certain cases, particularly at high protein concentrations, the dye may bind to the protein with... 

Delayed action cytotoxins that inhibit the synthesis of nucleic acids. They are obtained from various molds/fungi (Aspergillus flavus, Aspergillus parasiticus). They are colorless to pale-yellow crystalline materials melting above 450°F. The "B" toxins fluoresce blue in the presence of UV light while the "G" toxins fluoresce green. They are only slightly soluble in water, but are soluble in methanol, acetone, and chloroform. Aqueous solutions are "probably stable" and "probably tolerant" to chlorine at purification concentrations. 

An integrated pTAS system for the detection of bacteria including lysis, DNA purification, PCR and fluorescence readout has also been published recently [113]. A microfluidic plastic chip with integrated porous pol5mier monoliths and silica particles for lysis and nucleic acid isolation was used for detection (Fig. 8). A custom-made base device provided liquid actuation and off-chip valving by stopping liquid flow from the exits of the chip, utilizing the incompressibility of liquids. Detection of 1.25 x 10 cells of B. subtilis was demonstrated with all assay steps performed on-chip. 

Atkinson, I. J. Erikson, G. H. Daksis, J. I. Picard, P. Kits and methods for purification of nucleic acids using heteropolymeric capture probes and duplex, triplex or quadruplex hybridization in soln. utilizing fluorescent intercalating dyes. U.S. Pat. Appl. Publ. US 2003049673, 2003 Chem. Abstr. 2003, 138, 232955. 

Analytical procedures for foods are generally based on extraction with purified solvents following saponification with alcoholic potash. Purification of the extracts by chromatography on column or plates is followed by analysis of the purified extract using TLC, GLC or HPLC. Spectrophotometric or spectrofluorimetric methods may be used for quantitation of the hydrocarbons a collaborative study of a spectrophotometric method showed it to be applicable at the 2 fig/kg level. HPLC techniques using spectrofluorimetric detection have been described for which improved levels of detection are claimed. Benzo(a)pyrene produces substitution products with nucleic acids. Hydrocarbon deoxyribonucleoside adducts may be isolated from DNA by gel permeation chromatography, and the formation of hydrocarbon epoxides by mammalian enzyme reaction has also been demonstrated . The limit of detection of spectrophotometric and fluorimetric methods has been improved by three orders of magnitude by the use of laser-induced fluorescence procedures for the... 

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