A composition and a method for 5'-labelling polynucleotides undergoing solid phase synthesis wherein a phosphoramidite of an .omega.-hydroxylamine is condensed to a support-bound polynucleotide.

The primary and/or secondary structure of nucleic acid as well as its content and molecular weight can be analyzed in solutions by light scatter or fluorescence measurements after treatment with 3 or 4 ring aromatic cations which bind to single-stranded nucleic acids by cooperative association and induce their condensation (collapse). Preparative separation of nucleic acids of different types from the mixtures in the solution is also accomplished by the same principle and techniques wherein each...

A process for detecting specific nucleotide sequences, called targets, in which a special DNA probe molecule, called a probe-vector, is capable of transforming bacteria if and only if it is held in a circular configuration by base pairing to a target nucleic acid, said transformation resulting in the detection of a phenotype specified by the probe-vector, said detection establishing the presence, absence, or quantity of the target; and a probe-vector molecule for performing the process.

Nucleic acid hybridization probes are provided which comprise an N.sup.4 -(substituted amino)cytosine moiety, wherein the substituted amino group comprises a tag moiety, whereby the probe is detected. Methods of preparing probes of the invention, intermediates used in such methods, and methods of using the probes of the invention in hybridization assays are also provided. Typical tag moieties employed with the probes of the invention are biotinyl, aminothiadiazole and fluorescein derivatives, co...

The present invention relates to a process for producing deoxyribonucleic acids and/or ribonucleic acids (hereinafter designated as high-molecular nucleic acids), which is characterized by culturing aerobically a microorganism capable of producing deoxyribonucleic acid and/or ribonucleic acid in a culture medium containing hydrocarbon or carbohydrate as main carbon source, accumulating a substantial amount of deoxyribonucleic acid and/or ribonucleic acid and recovering the accumulated deoxyribon...

Free floating viruses are detected and sized by a method which combines fluorescent staining with the observation of a modulation of the fluorescence intensity by Brownian motion of the particles in combination with a particular spatial filter. Intensity modulation and fluorescence data provides a set of descriptors useful in distinguishing the type of virus involved, particularly if also combined with data regarding the scattering of light by the particles. The method and apparatus are also usa...

Free floating viruses are detected and sized by a method which combines fluorescent staining with the observation of a modulation of the fluorescence intensity by Brownian motion of the particles in combination with a spatial filter. Intensity modulation and fluorescence data provides a set of descriptors useful in distinguishing the type of virus involved, particularly if also combined with data regarding the scattering of light by the particles. The method and apparatus are also usable in conn...

A method for simultaneously isolating DNA, RNA and/or protein fractions from a crude biological mixture containing DNA, RNA and/or protein fractions is disclosed. The method comprises adding the crude biological mixture to an aqueous solution of cesium trifluoroacetate, the solution having a density from about 1.4 to about 1.6 g/ml, and centrifuging the resulting mixture under ultracentrifugation conditions.

A storage stable single phase aqueous composition is provided which is useful in isolatin nucleic acids from cell or virus cultures.

Modified nucleotides are provided which have the structure ##STR1## wherein R.sup.1 is a reactive group derivatizabale with a detectable label, R.sup.2 is an optional linking moiety including an amide, thioether or disulfide linkage or a combination thereof. R.sup.3 is hydrogen, methyl, bromine, fluorine or iodine, R.sup.4 is hydrogen, an acid-sensitive, base-stable blocking group or an acyl capping group, R.sup.5 is hydrogen or a phosphorus derivative, R.sup.6 is H, OH, or OR where R is a prote...