The Nucleic Acid Blot Analyzer II. ANALYZE, an image analysis software package for molecular biology

The Nucleic Acid Blot Analyzer, a new instrument providing high-speed imaging of 32P labeled nucleic acids, captures, stores and presents images in digital form, thus lending itself to rapid data handling and analysis as well as replacing conventional X-ray film autoradiography for many applications. A software package called ANALYZE has been specifically designed for the instrument in order to provide automatic or semi-automatic analysis for molecular biological techniques. The software includes image display manipulation, quantitative and positional analysis, as well as file maintenance utilities. The specific application of the software/hardware to various techniques is presented.     

Cotransformation of temperature sensitivity and nutritional markers in Neisseria gonorrhoeae.

Cotransformation remains the only tool for establishing linkage in Neisseria gonorrhoeae. Because of the difficulty of inducing auxotrophic markers via mutagenesis in this species, most previous studies have utilized antibiotic resistance and naturally occurring (auxotypic) auxotrophic markers. We have succeeded in isolating auxotrophic and temperature-sensitive mutants. The temperature-sensitive mutants have been characterized by their growth on complex and defined media at 31, 37, and 40 degrees C. Two of the mutants exhibited an unusual pattern of temperature sensitivity--growth on the defined medium but absence of growth on the complex medium at 37 degrees C. Both mutants, however, were temperature-sensitive on the two media at 40 degrees C. We have demonstrated linkages between markers isolated in our laboratory and the auxotypic markers of the clinical isolate RUG208. Ts-2 exhibited 85 to 95% linkage to Arg- and his-2 exhibited 40% linkage to Val-. In addition weak linkages were shown between his-2 and Arg- (2 to 6%) and between Arg- and Val- (3 to 5%). Linkages among his-2, Arg-, and Val- which could be demonstrated when deoxyribonucleic acid from strain F62 was used to transform RUG208 were absent when F62 was used as recipient for RUG208 DNA. Our data are consistent with a tentative map order of his-2, Val-, Arg-, Ts-2.     

Barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis>)-induced growth inhibition of algae: a review

Many field and laboratory studies have attempted to explain the inhibitory effect of rotting barley on algae. Early field studies lacked controls and replication and results depended on visual observations. Such studies offer information on barley bale field construction and application rates. In the laboratory, discrepancies in the barley variety used, algal species tested, barley liquor preparation and phenol extraction methodologies existed. Inconsistencies have led to different growth responses for the same species of algae tested, i.e. with some studies finding an inhibitory response and other studies reporting an accelerated growth response of algae. Two successful forms of investigation have been identified: (a) using commercially available compounds, i.e. with known shikimate-pathway-producing phenols and acids, which can then be combined with algal assays of different algal species and (b) using commercially available algal species from which batch cultures are grown, which are then added to barley liquor of different ages. Algal growth may then be investigated using in vivo fluorescence and the filtrate can be analysed via HPLC/MS. The identification of allelochemicals, which range from phenolics to quinones within the Poaceae family of which barley is a member, has received a lot of attention in recent years.