Improvements in the transfer and detection of separated nucleic acids, both RNA and DNA, are provided. For analysis of large DNA, the molecular weight segregated fractions of DNA are depurinated and fragmented to provide fractions having less than about 2 kb as single strands. With both RNA and DNA, the nucleic acid fractions are transferred after resolution to a chemically treated substrate and covalently affixed to the substrate. The resulting nucleotides affixed to the substrate are hybridize…

Molecular models for use in constructing, and experimenting with, the different secondary and tertiary structures of polynucleotides, using specially designed plastic blocks representing mononucleotides, are described. These models are composed of blocks that can be both assembled in vertical stacks to illustrate single-stranded, random coil, polynucleotides and joined in horizontal pairs to illustrate hydrogen-bonded nucleotide pairs. A combination of both these manners of assembly would illust…

This disclosure relates to a class of compounds which are utilized as biological stains in fluorescent microscopy. In particular, the disclosure relates to a method for detecting and identifying various structures in a biological sample which comprises treating said biological sample with a compound of the present disclosure to form a complex which emits fluorescence when irradiated with incident light. This class of compounds has been shown to be useful in detecting a variety of structures such…

A multiwell apparatus for the assay of microliter quantities of body fluids is provided which prevents fluid loss by lateral migration or gravity flow through a microporous membrane or ultrafilter. A sample is passed through a membrane to which an antibody has been bonded in order to harvest complementary viral antigens in the sample. The harvested viral antigen is converted to single strand DNA or RNA which then is deposited on a second membrane. The deposited single strand DNA or RNA is capabl…

A nucleic acid-protein conjugate which is specific with respect to a selected living cell is prepared by linking said nucleic acid to a protein specific to said living cell.

Method of binding nucleic acid to a nucleic acid-binding support comprising depositing the nucleic acid onto the support and then contacting the nucleic acid and the support with a liquid binding solution which is compatible with the support and which contains an organic solvent which is capable of binding the DNA to the support, for a period of time sufficient to effect the binding.

Microorganisms with low nucleic acid content are produced by acid treating of the microorganism. One embodiment relates to the extraction of so treated microorganisms after their separation from the acid treating fluid, using a strong base for the extraction. Another embodiment relates to the neutralization of the acid treating fluid containing nucleic acids prior to the introduction of this fluid into the fermentation zone, the anion of the acid and the metal cation used in the neutralization s…

The invention teaches a method and kit for purifying nucleic acid, such as DNA, from a sample, such as lysed cell or tissue sample. A sample is applied to an anionic exchange matrix column uniformly distributing the sample therein. The column bed is then washed with a weak ionic salt solution which is then removed. The anionic exchange material is optionally primed with an amount strong ionic salt solution which is insufficient to elute the nucleic acid from the column. The priming solution is t…

The present invention discloses an assay for nucleic acid which comprises the steps of; (a) providing a probe material comprising; (i) a sequence of nucleic acids complementary to a given target sequence and, (ii) a first ligand chemically linked thereto and capable of a specific binding reaction with an antiligand; (b) contacting the said probe material with an assay system comprising: (i) a suitable mediator, enzyme, substrate system capable of transferring charge to an electrode surface when …

The crosslinking agent contains an acylhydrazide moiety, through which it is linked to a cytosine residue on the first chain; and an .alpha.-haloketal moiety which, after attachment of the crosslinking agent to the first chain, is hydrolyzed to an .alpha.-haloketone moiety, through which linking is effected to the base-paired guanine residue on the second chain.