|
|
|
|
|
|
Simple and Inexpensive Fluorescence-Based Technique for High-Throughput Antimalarial Drug Screening. Martin Smilkstein, 2004.Radioisotopic assays involve expense, multistep protocols, equipment, and radioactivity safety requirements which are problematic in high-throughput drug testing . This study reports an alternative, simple, robust, inexpensive, one-step fluorescence assay for use in antimalarial drug screening . Parasite growth is determined by using SYBR Green I, a dye with marked fluorescence enhancement upon contact with Plasmodium DNA . A side-by-side comparison of this fluorescence assay and a standard radioisotopic method was performed by testing known antimalarial agents against Plasmodium falciparum strain D6 . Both assay methods were used to determine the effective concentration of drug that resulted in a 50% reduction in the observed counts (EC50) after 48 h of parasite growth in the presence of each drug . The EC50s of chloroquine, quinine, mefloquine, artemisinin, and 3,6-bis-  -(N,N-diethylamino)-amyloxyxanthone were similar or identical by both techniques . The results obtained with this new fluorescence assay suggest that it may be an ideal method for high-throughput antimalarial drug screening .
Integration Site for Streptomyces Phage  BT1 and Development of Site-Specific Integrating Vectors.Matthew A. Gregory, 2003.Despite extensive similarities between the genomes of the Streptomyces temperate phages C31 and
BT1, the attP-int loci are poorly conserved . Here we demonstrate that
BT1 integrates into a different attachment site than
C31 .
BT1 attB lies within SCO4848 encoding a 79-amino-acid putative integral membrane protein . Integration vectors based on
BT1 integrase were shown to have a broad host range and are fully compatible with those based on the
C31 attP-int locus .
Contributions of Atmospheric CO and Hydrogen Uptake to Microbial Dynamics on Recent Hawaiian Volcanic Deposits. Gary M. King, 2003.A series of sites were established on Hawaiian volcanic deposits ranging from about 18 to 300 years old . Three sites occurred in areas that supported tropical rain forests; the remaining sites were in areas that supported little or no plant growth . Sites >26 years old consumed atmospheric CO and hydrogen at rates ranging from about 0.2 to 5 mg of CO m-2 day-1 and 0.1 to 4 mg of H2 m-2 day-1, respectively . Respiration, measured as CO2 production, for a subset of the sites ranged from about 40 to >1,400 mg of CO2 m-2 day-1 . CO and H2 accounted for about 13 to 25% of reducing equivalent flow for all but a forested site, where neither substrate appeared significant . Based on responses to chloroform fumigation, hydrogen utilization appeared largely due to microbial uptake . In contrast to results for CO and hydrogen, methane uptake occurred consistently only at the forest site . Increasing deposit age was generally accompanied by increasing concentrations of organic matter and microbial biomass, measured as phospholipid phosphate . Exoenzymatic activities (acid and alkaline phosphatases and  - and ß-glucosidases) were positively correlated with deposit age in spite of considerable variability within sites . The diversity of substrates utilized in Biolog Ecoplate assays also increased with deposit age, possibly reflecting changes in microbial community complexity .
|
© 2005
Transgalactic Ltd (manufacturer of Bioscreen C software) |
Privacy Statement | P.O. Box
1393, 00101 Helsinki, Finland,
Last modified: May 25, 2005
| ||||||
