The determination of microbial biomass and the activity of microorganisms in soil presents a complex analytical problem for assays. Numerous studies have demonstrated that classic methods, which require the isolation and subsequent culture of microorganisms, are not adequate for enumerating microorganisms in soil. Viable counts underestimate the microbial community when compared with direct count techniques [1–31 or with estimates of muramic acid in the prokaryotic cell wall [4]. This discrepancy has been attributed to the selective growth of microbes on artificial media, the formation of a single colony from bacterial aggregates, and the difficulty of quantitative removal of organisms from soil particles [4, 5]. Direct counting methods are also subject to technical difficulties when applied to soil systems [5]. For example, cells may be hidden in soil particles or overlapping organisms, particularly in aggregates of organisms attached to particles, and the conversion from counts to biomass, by estimating volumes of the microorganisms, can result in large errors.