The generation in vivo of plasmids deleted at specific sites in strains of Klebsiella pneumoniae containing R plasmids, by treatment with high concentrations of acridine orange (1.2 mg/ml) at 42 degrees C are reported. These deletions seem to be site specific because loss of specific restriction fragments after digestion with restriction enzymes was demonstrated.

We have developed a quick, simple technique for the fluorescent staining of bacterial endospores. This technique was developed using Bacillus subtilis endospores. Our technique requires minimal sample heating so it can safely be carried out entirely in a glove-box. The endospores stain diagnostically as an oval with a standard fluorescent nucleotide stain, acridine orange.

Over the past 25 years, various methods have been developed to measure sperm DNA strand breaks in situ. Currently, there are four major tests of sperm DNA fragmentation, including the Comet, Tunel, sperm chromatin structure assay (SCSA) and the acridine orange test (AOT). The Comet assay is a light microscope technique where the sperm cells are mixed with melted agarose and then placed on a gla...

Quantitative studies of biochemical development in embryos frequently are inadequate without concurrent histochemical correlation because alone they offer only limited information about the distribution in tissues of the substances under study. This is especially true of the ribonucleic acids (RNA) of which only relatively few histochemical studies have been done in developing embryos. In the c...

HE genome in Escherichia coli K-12 exists normally as one ring of doublestranded DNA (CAIRINS 1963). The fertility factor, F, is responsible for the ability of certain strains to act as genetic donors. F may exist as an autonomously replicating element (in Ff strains) or be integrated into and replicate with bacterial genome (in Hfr strains) (WOLLMAN, JACOB, and HAYES 1956). Multiplication of t...

For febrile neutropenic patients who received hematopoietic stem cell transplantation, the Gram stain-acridine orange leukocyte cytospin (AOLC) test and the differential-time-to-positivity method (DTP) were performed. As a diagnostic tool for catheter-related bloodstream infections in these patients, the Gram stain-AOLC test has a lower sensitivity than does the DTP method but acceptable positi...

Mycoplasma colonies and Mycoplasma cells in preparations from infected milk and lymph nodes were observed for their fluorescent qualities after treatment with acridine orange. Mycoplasma colonies fluoresced brilliant red or red-orange. When treated after exposure to ribonuclease, the colonies fluoresced lime-green. There was no fluorescence when both ribonucleic acid and deoxyribonucleic acid w...

Mouse peritoneal macrophages exposed to type-specific polysaccharide and peptidoglycan (PPG) from group A streptococci undergo marked morphologic and biochemical changes. The cells show increases in size and an increased number of lysosomes as demonstrated by vital staining with acridine orange. There are significant elevations in the levels of both lysosomal and nonlysosomal enzymes. Higher do...

Characteristics are described of small-colony variants of Xanthomonas campestris NRRL B-1459 which are frequently encountered when routine culture maintenance procedures are employed. In contrast to the parental type, smallcolony variants were shown to be resistant to a number of antibiotics, to acridine orange, and to phage which are virulent for the parent colony type. Sensitivity to ultravio...

Understanding the origin of the dramatic temperature and density dependence of the relaxation time of glass-forming liquids is a fundamental challenge in glass science. The recently established “density-scaling” relation quantifies the relative importance of temperature and density for the relaxation time in terms of a material-dependent exponent. We show that this exponent for approximate sing...