Charles River offers full-service electron microscopy (EM) with both scanning and transmission capabilities in multiple locations. Typical applications include quantitative evaluations of myelin thickness in peripheral nerves for neurotoxicity, viral particle characterization, evaluations of tissue/medical device interface, characterization of red blood cell morphology and many others.
Both specimen preparation and the selection of a fixative are critical to visualization at the cellular level. Recognized for our experience in this field, we provide GLP-compliant transmission electron microscopy (TEM) services for ultrastructural pathology and viral particle identification, tabulation, quantification and characterization in support of the FDA Points to Consider (PTC) documents. Scanning electron microscopy (SEM) services provide additional topographic detail for the evaluation of device products, such as tissue luminal surfaces and stent-implanted vessels.
Our experienced staff is available to provide guidance in protocol design for the most appropriate collection, preparation and evaluation of biologic samples to ensure sample integrity.
Typical Applications
Microscopy & Imaging Services
- Transmission electron microscopy (TEM)
- Scanning electron microscopy (SEM)
- Light microscopy
- Dual-energy X-ray absorptiometry (DXA)
- Quantitative computed tomography (QCT)
- Micro-computed tomography (Micro-CT)
- Digital radiography
Transmission Electron Microscopy
Ultrastructural morphology procedures enable the visualization of unique details of the structure and the quantification of cellular organelles. This imaging technique gives investigators precise data on mitochondria, peroxisomes, smooth and rough endoplasmic reticulum, cytoplasmic granules and inclusion bodies, which assist in determining a compound’s mode of action, understanding the pathogenesis of toxicologically related lesions and establishing “no observable effect” levels. Our investigators perform a variety of ultrastructural analyses, ranging from simple qualitative evaluations to enumeration of lysosomes and peroxisomes, as well as morphometric studies measuring collagen and amyloid fibrils. Subtle lesions not visible in standard H&E slides can be observed and likely pathogenic mechanisms may be identified.
Scanning Electron Microscopy
SEM enables the investigator to examine the surface topography and morphology of cells, tissues or medical devices by scanning a beam of electrons across a sample. This imaging technique may be employed in studies in which exterior damage or integrity is of concern. Tissue samples can be mounted such that alterations in cellular growth can be monitored. Samples can be photographed on an SEM and reviewed by our veterinary pathologists.
Resin Embedding for Light Microscopy
For fine-detail light microscopy, very thin resin-embedded sections can be prepared in our laboratories. Our scientists agree that tissues fixed in osmium tetroxide, embedded in Spurr resin and sectioned with a diamond knife at one micron allow for the visualization of greater cytological and nuclear detail than paraffin sections. Epoxy resin produces little shrinkage, so it is the preferred medium for tissues requiring measurements.
Other Imaging Equipment
In addition to our microscopy capabilities, we have extensive imaging laboratory services that can support your research and development efforts. DXA, QCT, micro-CT and digital radiography are all available.
For more information, please contact us at 1.877.CRIVER.1 or askcharlesriver@crl.com.