If a virus is present with visible and otherwise noticable symptoms,
but fails to be detected with common lab tests, can the use of an
electron microscope be relied on to determine it's true presence? How
reliable would this method be? What time and involvement would be
expected? Where can one find documentation of past examples of this?

larry farrell

1. Electron microscopy requires a relatively high
titer of the virus for
visualization/identification. If the titer is
less than about e8-e9/ml, you are unlikely to find it.

2. Finding the virus and recognizing it as such
often depends on knowing what the virus looks
like. There are all kinds of things one runs
across in crude preparations that look
surprisingly regular and appear to something of
interest but are actually cell debris of one sort
or another. Without some idea of what you are
looking for, you can easily be led astray by what
you see.

3. Time and involvement depends on what kinds of
samples are being used, what equipment is needed
an available to prepare the samples, what kind of
scope is being used, etc., etc., etc. Many
intangible variables.

4. Documentation can be found all of the primary
literature. Go looking.
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mike mcwilliams

This would usually be inappropriate, as PCR is a well established method
of amplifying very low signal.

Mind you it won't give you much of an idea of how infected one would be,
but that one is indeed infected, perhaps at a low level.

larry farrell

Actually, quantitative PCR can also give a
reasonable idea of the level of infection.

--
Larry D. Farrell, Ph.D.
Professor of Microbiology
Idaho State University
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mike mcwilliams

I hadn't heard of qPCR actually being used clinically yet... If that so,
could you point me to some info about it? I always thought it had the
potential.