Facilities at the CRL
Histology
Our histology laboratory combines traditional and state-of-the-art technologies for preparation of tissues
for histopathological assessment. High throughput systems for embedding, processing, staining and
reading of specimens are contained within the ISO 17025 accreditation framework: 'Method for testing
crustaceans for pathogens and notifiable diseases by histological analysis’. High-resolution digital
image capture systems and user-protected data storage ensure rapid and auditable result trails. The
laboratory is also equipped with a Laser Dissection Microscope (LDM) capable of capturing very small
samples from formalin-fixed paraffin embedded or frozen (cryotomy) tissue sections. Micro-dissected
samples can be downstream analysed for the presence of specific RNA, DNA and even protein markers as
appropriate.
Electron Microscopy Unit
Our Electron Microscope unit houses both a Transmission Electron Microscope (TEM) and a Scanning Electron
Microscope (SEM). TEM allows for ultrastructural examination of cells for changes caused by exposure to
pathogens and environmental stressors. Further it provides a key resource for the identification of novel
pathogens (from viruses to parasites), particularly prior to the development of molecular tools for their
diagnosis. As such, TEM is the only means of directly visualising viral pathogens such as the White Spot
Syndrome Virus (WSSV).
The SEM scans electrons across the surface of a sample and enables surface detail to be observed,
producing 3D images. SEM is used for parasite identification and to study the surface details of
parasites, points of attachment and hooks etc. Both the TEM and SEM within our laboratory possess
facilities for x-ray microanalysis, enabling for elemental analysis and mapping of the position of
these elements (e.g. heavy metals) within the sample.
Molecular Biology
The molecular Biology function houses an internationally recognized team of molecular diagnosticians and
researchers that cover a wide range of aquatic animal health topic areas. Currently, the function is
seeking flexible scope ISO/IEC 17025 accreditation for the confirmation of a wide range of fish,
shellfish and crustacean pathogens including viral haemorrhagic septicaemia virus (VHSV), infectious
haematopoietic necrosis virus (IHNV), epizootic haematopoietic necrosis virus (EHNV), infectious
salmon anaemia virus (ISAV), koi herpes virus (KHV) and specifically in relation to crustaceans,
detection of Taura syndrome virus (TSV), white spot syndrome virus (WSSV) and yellowhead virus (YHV).
The function routinely utilises state-of-the-art molecular diagnostic technologies and is fully
equipped to undertake automated nucleic acid extraction, real-time and traditional PCR and
sequence analysis. The laboratory also has the capacity to undertake pathogen detection using micro-array
technologies and labelling using in situ-hybridisation.
Aquatic Services Function (experimental facility)
The Aquatic Services function (ASF) provides managed tank and aquarium facilities to demanding UK Home
Office and Good Laboratory Practice (GLP) standards. Here native and exotic freshwater and seawater
species (finfish, shellfish and amphibians) are reared and/or held to support the work of science groups
within the CEFAS Weymouth Laboratory and beyond. The function operates and manages numerous flexible
tank systems where temperature, day-length and salinity may be computer controlled and monitored 24
hours/day. The aquarium system is capable of handling up to 300m3/day of dechlorinated, UV sterilized,
potable freshwater and a similar quantity of filtered and locally UV treated seawater. In addition up
to 30m3/day of untreated seawater is available to some tanks (specifically for the long term holding
of shellfish). All the effluent from the Experimental Facility is ozone sterilised before release
from the facility.
The Aquatic Service Function is capable of running both short term (days/weeks) and long-term studies
(months/years) across a range of disciplines and requirements. This includes research and development
work, therapeutant and vaccine testing, behavioural and feeding studies, crustacean incursion studies
and shellfish depuration and bioaccumulation studies. Current customers include both public and
commercial organisations. The facility is fully available to the CRL for crustacean diseases and
is utilised for challenge studies and generation of reference materials for distribution to Member
State National Reference Laboratories.