High
resolution 3D block face imaging for biological samples with fast acquisition
rates and minimal sample damage
JENA/Germany, SAN DIEGO/USA
In collaboration with the National Center for Microscopy and Imaging
Research (NCMIR) at the University of California San Diego, ZEISS releases a
new Focal Charge Compensation module for block face imaging with ZEISS
GeminiSEM and 3View® from Gatan, Inc. Focal Charge Compensation expands
versatility and considerably increases data quality without prolonging
acquisition times and enables easy imaging of even the most charge-prone
samples. Resin-embedded tissues and cells can be imaged without charging
artifacts, while the pixel dwell time is reduced. Decreasing beam exposure time
not only ensures fast acquisition rates, but also guards against sample damage,
which is key to acquiring reliable and reproducible 3D data. Professor Mark H.
Ellisman, Director of NCMIR, says “Focal Charge Compensation will breathe new
life into block face scanning electron microscopy by allowing high quality
imaging of previously intractable specimens, including legacy samples prepared
with traditional electron microscopy stains.”
Preventing charging effects
This extension of the 3View® system from Gatan, Inc
eliminates specimen charging. A gas injection system consisting of a tiny
capillary needle is precisely located above the sample. Nitrogen is guided through
this needle directly onto the block face surface while the chamber is
maintained under high vacuum. This eliminates charging without degrading image
quality. The needle retracts automatically during the cutting cycle so the
workflow is uninterrupted and high acquisition rates are maintained.
Producing thousands of serial images in a single day
The 3View® system consists of an ultramicrotome directly
integrated into the vacuum chamber of the ZEISS Sigma and ZEISS GeminiSEM field
emission scanning electron microscopes. It enables automated serial block face
imaging of embedded samples (e.g. cells or tissue) with a slice thickness down
to 15 nanometers. The sample is continuously cut and imaged, and a
three-dimensional rendering of the sample with nanometer-scale resolution can
be reconstructed.