This collection includes those
samples coming from routine diagnostic activity which are considered valuable
in terms of viral content. The reasons for which materials are conserved and
included in the collection are basically due to their peculiarity as regard to
species or type of virus detected. In fact, they are mostly rare,
non-cultivable, uncommon, unidentified or potentially new viruses, often from
Indeed, they have all been
characterized by electron microscopic observation. In fact, the viral
positivity is intended as presence of virions ascertained by using negative
staining electron microscopy as identification method.
Virion identification is based
on morphology. Thus classification is not necessarily referable to a taxa
(family, genus, species etc.) but is often defined with a “generic” name, that
may be often related to their morphological aspect (presence of the suffix
“–like” in the name).
In some cases, a better
taxonomic identification (up to species or to strain definition) may be given
if the examination has been done using an immune-electron-microscopy (IEM)
method, i.e. by using specific “known” sera or antibodies in order to concentrate
and aggregate virions in the form of immune-complexes.
Each pathological material not
necessarily contains just one virus. In fact, it is not uncommon to detect two
or more viruses in association, often acting in a synergic way, especially in intestinal
The amount of virions present
in each preparation may vary considerably. A semi-quantitative evaluation of
the viral contents is always given during observation with reference to a scale
of positivity ranging from 1 to 5 +.
In the collection the
materials may be present in the form of raw material (as it has been sent to
the laboratory) or in the form of supernatant from the centrifugation (6500rpm
x 30 min) of the extract/homogenates (10% w/v in distilled water) prepared from
the original materials.
Each sample included in the
collection has the exact amount of available material expressed in gr or ml
according to the relative form.
Quality management system
IZSLER laboratories, that
supply biological resources to IBVR, use testing methods performed according to
UNI EN ISO/IEC 17025 quality system. In addition, the EM laboratory is taking
part since 2000 to an international quality ring test named External Quality
Assessment (EQA) organized by Robert Koch institute – Berlin.
THE LIST OF AVAILABLE
MATERIALS, ACTUALLY OVER 800, COULD BE OBTAINED BY DIRECTLY CONTACTING THE
RESOURCE SPECIALIST (SUBSTR@IZSLER.IT; ENRICA.SOZZI@IZSLER.IT).
THEREAFTER, THE MATERIALS
COULD BE FURNISHED BY ESTABLISHING A SCIENTIFIC COLLABORATION AND SIGNING AN