Preconcentration of Microorganisms Into a Tiny Volume of Liquid for Enhanced Spectral Detection (original) (raw)

WORLD SCIENTIFIC eBooks, 2008

Abstract

Concentration of 1-micron-size micro-organisms from about 100 ml of liquid, whether drawn from a bio-aerosol collector or from an environmental water source, into a volume of 1 to 2 ml. is achieved by a liquid flow system including a reversible filter through which filtered liquid can be recirculated or disposed of and from which a concentrated sample is recovered by opening a solenoid valve leading to a detector or to a collection container and reversing the pump for a short time. The reversing action flushes the collected particles off the filter and into the detector or container. The effectiveness of this approach was demonstrated by measuring the cumulative fluorescence of 1-micron-size blue fluorescent microspheres versus cumulative volume withdrawn from our WEP collector after capture from an aerosol suspension of about 140 particles/ml drawn from a test chamber over a 5-minute period at a sampling rate of 500 liters/minute. As the liquid was being withdrawn from the WEP collector, it was filtered at a rate of 1 ml/second and the filter back-flushed with small portions of filtrate at 1-minute intervals. The relative cumulative concentration of captured particles in the first back-flushed 1-ml fraction was around 56 as compared with a value of 1.4 in the first 60-ml filtered fraction, which constitutes a liquid-to-liquid concentration enhancement by a factor of 40 and an air-to-liquid concentration factor of >1.25 × 106.

Nathan Schattke hasn't uploaded this paper.

Let Nathan know you want this paper to be uploaded.

Ask for this paper to be uploaded.