Grey squirrels in central Italy: a new threat for endemic red squirrel subspecies

n/

Novel techniques for rapid bacteriological monitoring of drinking water

In the United Kingdom, the microbiological safety of drinking water supplies is currently assured by monitoring for the absence of the faecal indicator organisms, total coliform bacteria and Escherichia coli. Monitoring work of this type makes up the bulk of the workload of the typical microbiology laboratory in the water industry. However, the most popular method, membrane filtration, imposes a delay of 18 hours to obtain a presumptive result, and can take up to 72 hours to provide a confirmed result. These delays are a handicap in giving a prompt response to incidents involving the contamination of water supplies. There is therefore a need for faster techniques which preserve the accuracy and reliability of the traditional methods. Fortunately, there are a number of new and rapid techniques for the labelling and detection of single bacterial cells, which could be adopted in the water industry for the enumeration of coliforms. Using these techniques, the requirement for culture of the bacteria can be avoided, and the test carried out in less than one working day. Techniques adequately to separate bacterial cells from water samples remain to be developed, although recent antibody-mediated separation systems seem very promising

Entente and argument: Britain, France and disarmament, 1899-1934

If there was one subject in particular on which decades of Anglo-French entente, or at least cordiality, never produced anything like real harmony, it was disarmament..

A highly sensitive assay for adenosine triphosphate employing an improved firefly luciferase reagent

An improved firefly luciferase reagent allowed reliable detection of as little as 80 fmo1/1 adenosine triphosphate (ATP). Contamination by ATP of the deionized water diluent limited the sensitivity of the assay in some laboratories. The reagent can be used to measure ATP from less than ten bacterial cells if care is taken to eliminate ATP from equipment and reagents

An evaluation of the performance of ten commercial luminometers

An assessment has been carried out of the relative performance of ten instruments for quantification of adenosine triphosphate (ATP) by the firefly luciferase assay. The instruments evaluated were Amersham Amerlite Analyser, Dynatech Tube Luminometer, Dynatech Multiplate Luminometer, Dynatech Camera Luminometer, Hamilton Lumicon, LKB 1250 Luminometer, LKB 1251 Luminometer, Lumac Biocounter M2010A, Turner 20 TD Luminometer and a prototype version of the CLEAR Speed Tech 2000. An 800-fold difference in sensitivity was found between the most sensitive (Lumac, Turner) and the least sensitive (Dynatech Tube) of the conventional instruments. The Dynatech Camera Luminometer which worked on a completely different principle to the other instruments was about 5000 times less sensitive than the best of the photomultiplier tube instruments. The relative sensitivity of the instruments was maintained regardless of whether solutions of ATP in water or trichloroacetic acid extracts of bacteria were analysed. An analysis of 960 ATP bioluminescence assays showed that data obtained from such measurements are normally distributed