The "Most Probable Number" estimate and its confidence limits.
The dilution method is used to obtain an indirect count of microorganisms, e.g. fecal bacteria commonly used as human contamination indicators, in a suspension.
The Most Probable Number estimate provides a quantification of dilution method results.
This estimate is commonly obtained by using Poisson distribution.
Although the use of binomial distribution leads to lower estimates, only a 5% maximum difference was noted, which is negligible in terms of MPN precision.
Relative MPN bias is considerable (35% on average) and apparently varies with true bacterial density; however the binomial model reduces its magnitude by 5-8%. A new method for determining Bayesian intervals based on an equilikelihood criterion is presented.
Mots-clés Pascal : Qualité eau, Coliforme, Feces, Pollution eau, Indicateur biologique, Limite confiance, Loi Poisson, Nombre le plus probable
Mots-clés Pascal anglais : Water quality, Coliforms, Feces, Water pollution, Biological indicator, Confidence limit, Poisson distribution
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 93-0397572
Code Inist : 001D16A02. Création : 199406.