Merck Milliflex Quantum User Manual page 3

1. Introduction
Milliflex Quantum System is a rapid fluorescence-based technology for fast quantitative
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detection of contaminants over a broad range of filterable matrices. This easy to use and
simple system can detect viable microorganisms filtered on a membrane down to one
CFU per sample. The non-destructive method allows the identification, by any method, of
any microorganisms detected during the initial fluorescence reading. Sample preparation
is performed by means of membrane filtration using the Milliflex system that ensures
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consistent and reliable results.
1.1 Chemistry of the reaction
The Milliflex Quantum system uses proven technology based on a universal enzymatic
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fluorescent staining of viable microorganisms.
After a filtration step with Milliflex Oasis sample preparation devices, all microorganisms
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retained on the membrane are stained by a fluorescence viability marker. The reaction
consists of an enzymatic cleavage by active microbial metabolism of a non-fluorescent
substrate. Once cleaved by the cell's metabolism, the substrate liberates free fluorochrome
into the microorganism cytoplasm that cannot leave the cell due to its hydrophilic nature.
The signal is thereby naturally amplified by accumulation of the fluorochrome inside
the cells and can be easily detected by exposure to the excitation wavelength of the
fluorescence dye in the Milliflex Quantum reader and visually counted (or via usage
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of Milliflex Quantum Camera and the dedicated software).
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1.2 Principles of the procedure
The procedure is easy and requires limited training & skills: sample contaminants are
collected by membrane filtration using the Milliflex Oasis system. After a short incubation
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time, media cassettes are removed. Each Milliflex Oasis ® membrane is then transferred
onto a cellulose pad pre-soaked with 2 mL of staining solution and incubated for 30 minutes
at 32.5 °C ±2.5 °C. Fluorescent micro-colonies are counted using the Milliflex Quantum
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reader or on a PC screen using a dedicated camera and software. After reading, membranes
can be re-incubated on media for later micro-organism collection and identification if
contamination of the sample was detected.
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