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At a recent
open seminar in Nuremburg, Dr Gerhard Pieper from IBM in Mainz
(Germany) presented details of their implementation of the ChemScan
RDI rapid microbiology test system (Chemunex SA, France) for
the real-time monitoring and control of microbial contamination
in their state-of-the-art hard disk manufacturing facility.
The manufacture
of hard disks and semiconductors requires the highest level of
cleanliness possible before the disks go through a coating process.
This is done by washing machines which use ultra-pure water. The
presence of microbial contamination, unlike inert particles, is
particularly problematic as organisms can multiply to relatively
high levels. Other monitoring methods used in this industry like
LPC (liquid particle count) or TOC (total organic carbon) are
not always sensitive enough to detect this contamination before
they multiply to a critical level.
Dr Pieper
had identified a number of critical control areas within the washing
machines and the manufacturing facility that could be prone to
microbial contamination. IBM had previously used traditional plate
counting methods to monitor microbial contamination in these areas.
However, Dr Pieper explained that these tests are not ideal since
they require 3-5 days to provide results, may not detect all micro-organisms,
are labour intensive and expensive when out-sourced to contract
laboratories (many facilities do not have microbiology laboratories).
In evaluating
the situation, IBM concluded that they wanted to have real-time
microbiology results that allowed proactive monitoring and control
of these critical manufacturing operations. However, as many facilities
do not have microbiologists, any new testing method had to be
easy to use without investment in new laboratories, provide results
that required no interpretation (direct counts), be comparable
at their facilities world-wide and at a reasonable cost.
Initially
methods based on epifluorescence microscopy and ATP bioluminescence
were evaluated and rejected due to the need for highly trained
operators, repeatability of measurements, high analysis time and
a lack of detection sensitivity.
IBM then completed
an extensive 2 month evaluation of the ChemScan RDI which
is based on membrane filtration of samples, fluorescent labelling
of single live microbial cells trapped on the surface of the membrane
and their detection and counting using laser scanning analysis
in the ChemScan RDI instrument. They concluded that the
new method had the sensitivity to detect and count down to one
micro-organism in samples within 1 hour of sample collection,
did not require any investment in special laboratory facilities
and could be used by production personnel after 1 days training.
Dr Pieper
explained that the Mainz facility currently use the system for
improving control and for the routine monitoring of both the ultra-pure
water systems and the cleaning machines. He indicated that the
availability of sensitive results in near real-time allows them
to control microbial contamination at the lowest level and to
optimise cleaning procedures. This guaranties the best achieveable
machine performance and improved monitoring costs overall.
Commenting
after the presentation, Dr Michael Brailsford, Director of Marketing
& Sales at Chemunex said, "After establishing the ChemScan
RDI as a new innovative method for rapid testing of high purity
water systems in our first target market within the pharmaceutical
industry, we have been working hard to expand its application
into other industries. The semiconductor market was an obvious
target, where the need for monitoring low level microbial contamination
is at least as important." Dr Brailsford continued, "To enter
this market with two of the initial installations at IBM, the
second unit is installed in the USA, is obviously very exciting
for us and has provided a solid platform for the continued introduction
of ChemScan RDI to this market".
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