Re: Future prospects

/G=Gerhard/S=Nebe-von-Caron/OU=1890CHPE/O=TMGB.URC/@LANGATE.gb.sprint.com
Wed, 13 Sep 1995 11:55:00 -0400

Hi Hazel

I attach the abstract of the best review on the shelf at the
moment.

Regarding you questions I would say that the technology is
sorted out, the request or acceptance is missing.

I work in that field myself now for about ten years, having
measured bugs on the good old Ortho, the Facsscan and
analyser, the Skatron Argus and now the Coulter Elite and
the EPICS XL/MCL. We happily measure them with 15mW
air-cooled laser power and on the last ISAC Howard even
showed his "pocket-version" with the tiny HENE laser. So
signal intensity is clearly not the problem.

Once we have sorted out the staining protocol even untrained
people can run bacterial samples on the EPICS XL without
trouble. The latter one we use without any modification to
analyse for example dental plaque for simultaneous viability
and antibody-stains without problems even with the
autoloader (and so does the US army I believe). Thus I do
not think it is "ease of handling" either.

What has improved acceptance quite a bit is the use of the
Autoclone on the Elite to sort single cells on agar plates.
This makes it easier for the microbiologists to relate to
the fancy coloured dots and clusters on the computer screen.

Apart from the cost, the three things that remain a problem
is the lack of "cd-markers" for species differentiation, the
numeric limitations of the system and the fact that it is a
single channel instrument, not a 96 well reader. Despite
that flow cytometers are geared for looking at high numbers
of particles, (not volumes) there is a limit to what
background you can cope with even just looking at 4 log
kill. Below 0.1% noise becomes very painful That is what
usually also limits the counting sensitivity. To see a
cluster appearing you would probably want to see about 100
events to form it in whatever volume you are prepared to
sample. This means some form of preamplification of which
growth is still the most potent (>10^12)...

Gerhard Nebe-v.Caron
Unilever Research, Colworth Laboratory Sharnbrook,
Bedfordshire
GB - MK44 1LQ
Tel: +44(0)1234-222066
FAX: +44(0)1234-222344
E.mail: gerhard.nebe-von-caron@urcgb.sprint.com






Title: Recent advances of flow cytometry in fundamental and applied
microbiology
Author: Fouchet, Pierre; Jayat, Chantal; Hechard, Yan; Ratinaud, Marie Helene;
Frelat, Gerard
Source: Biol. Cell 1993 78 01/02/95 95-109
Year: 1993
Country: Fontenay-aux-Roses, 92265, Fr.

Abstract A review with 215 refs. focusing on recent applications of flow
cytometry (FCM) in microbiol. research (1987-mid 1992). It tries to give a
scope of the important breakthroughs which occurred in this field during this
period. The tech. difficulties of microorganism anal. by flow cytometry is
briefly appraised. The significance and the limits of the different microbial
cell parameters attainable by flow analyses are systematically evaluated: light
scatter for cell size and structure, fluorescence measurements for
quantification of cellular components, microbial antigen detection and cell
physiol. activity estn. Emphasis is given on the new technol. advances which
appeared in the last two years. The second part of the review is devoted to the
anal. of the usefulness of flow cytometric approach in the different fields of
microbiol.: fundamental studies in microbial physiol., differentiation,
microbial ecol. and aquatic sciences, medical microbiol., parasitol., microbial
pharmacol. and biotechnol.

______________________________ Reply Separator _________________________________
Subject: Future prospects
Author: hlr@aber.ac.uk at INTERNET
Date: 12/09/95 22:02

We are preparing a review on various aspects of flow cytometry in microbiology
and like all good reviewers we will include a "future prospects" section. We
have ideas of our own for this, but would also be pleased to hear from anyone
else about how they would like flow cytometers to develop to make them more
useful for the microbiologist.

Do you currently find the sensitivity of your flow cytometer limiting? Are
there flow cytometric techniques that should but don't work for microbes? Does
the future lie in better instrumentation or in better dyes? Please remember to
include in any correspondence the make and model of flow cytometer that you
use.

If you would like to offer your opinions then you can Email me on:
hlr@aber.ac.uk
or if you prefer you can fill in the feedback form on my website:
http://pcfcfh.dbs.aber.ac.uk/

If anyone else expresses an interest in this information then I will Email a
summary to the list or to interested individuals. If you want your views to
remain anonymous please let me know.

Of course any very recent (1995) (p)reprints in this field that you think we
should include would also be most welcome.

Snail address:
Dr Hazel M. Davey,
Institute of Biological Sciences,
Edward Llwyd Building,
University of Wales,
Aberystwyth,
SY23 3DA
WALES, U.K.

Many thanks in advance for your help,

Hazel

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| Dr. Hazel Davey (hlr@aber.ac.uk), Univ. Wales, Aberystwyth, UK, SY23 3DA |
| WWW : Flow Cytometry | Welsh | Brewing : http://144.124.112.37/index.htm |
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