The value of binding enthalpy change (ΔH) due to DNA–ligand complexformation has been determined by Van’t–Hoff mode having dependence of binding constant (K) on the reverse value of absolute temperature. Calculations that were carried out for DNA–ethidium bromide and DNA–mitoxantrone complexes showed, that if ΔH is determined from the values of K at two different temperatures, the calculated va...

The porphyrin photosensitizer, meso-Tetra (4-N-methyl-pyridyl) porphine tetraperchlorate is shown to unwind supercoiled ColEI DNA at a somewhat lower concentration than ethidium bromide. In contrast to this, the Fe(III) chelate of T4MPyP cannot unwind supercoiled DNA. It is concluded that these results corroborate our previous findings that, despite its large bulk, T4MPyP is fully capable of in...

The effects of various carbon sources and of antibiotics on the morphology of hypha cells of the fungus Ustilago cynodontis is described. Nonfermentable substrates promote readily reversible yeastlike colonies from hypha cells: all the hypha cells spread on these substrates give rise to yeastlike colonies that revert to the mycelial phenotype when transferred to glucose medium. Among the antibi...

Detection of low concentrations of DNA is important in vision research because many animal models only provide scant samples of ocular tissue. Quantitative analysis of low concentrations of double stranded DNA is now feasible using fluorometry with newer fluorophores. This technique offers a rapid way to evaluate the DNA content of samples based on the measurement of fluorescence enhancement em...

Purified mitochondria from the petite positive yeast Torulopsis glabrata contain a circular deoxyribonucleic acid (DNA) with a length of 6 mum and a buoyant density of 1.686 g/cm3. This DNA is absent from ethidium bromide induced respiratory-deficient mutants.

Insecticides are chemical agents used to control insects, but humans are usually exposed to insecticides and this may have a long term toxicological effects on their health. Different brands of insecticides including Baygon, Mobile, Mortein and Total were subjected to Ames spot Forward Mutation Assay, using Escherichia coli. The assay was examined for the presence of revertant strains of the or...

Follicular atresia has been examined previously by various biochemical and histological methods. The aim of this study was to compare, for the first time, detection of granulosa cell apoptosis by biochemical DNA analysis and microscopic examination of fresh granulosa cell morphology with the established method of detecting atresia by histology in equine follicles. DNA extracted from granulosa c...

The binding of ethidium bromide to chicken erythrocyte core particles results in a step-wise dissociation of the structure that involves the initial release of one copy each of histones H2A and H2B. Quantitation of the dissociated DNA reveals that a critical amount of drug is required for the dissociation. Above the critical value, the dissociation is time dependent, reversible, and independent...

and Implications The ELISA assay is a more rapid and sensitive method for PCR product detection than conventional gel electrophoresis. The PCR/ELISA allows for the processing of numerous samples, is relatively inexpensive and eliminates the need for electrophoretic and photographic equipment as well as the use of potential carcinogens such as ethidium bromide which is utilized in the gel electr...