Cryo-EM Services

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Cryo-EM Services by Creative
Biostructure
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Electron microscopy (EM) has become an extremely
popular method for the ultrastructural study of
macromolecules, cells and tissues. With our
in-house EM platform at Creative Biostructure, we
are mainly focused on the use of cryo-EM
technique to determine the structure of large
macromolecules and their complexes with small
ligands, proteins and nucleic acids. Other types
of samples are also acceptable and can be handled
with scanning electron microscopy (SEM) or
transmission electron microscopy (TEM).
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(1) Sample preparation After protein
purification, these samples will be treated by
cryo-fixation. In this method, protein samples
are placed on a specially treated EM grid
consisting of tiny holes in a film supported by a
metal frame. The grid is then plunged into liquid
ethane to flash-freeze it, resulting in the
protein samples being embedded in a thin layer of
vitreous ice. Once the frozen hydrated grid is
prepared, it is placed in the electron microscope
and kept at approximately -180 K throughout the
experiment.
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(2) EM imaging and data processing
High-resolution EM images are obtained and data
processed by our experienced scientists. We
provide services that include Data
collection Initial 3D model calculation Beam-ind
uced motion correction Micrograph
screening Automatic particle picking and
normalization 2D, 3D classification and
refinement.
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(3) Model building and refinement Using our
high-performance computers and software packages,
we are able to interpret EM maps and reconstruct
them into three-dimensional structural models
that satisfy principles of physics and
stereochemistry. Our scientists are also very
experienced with challenging targets such as
membrane proteins by manual intervention to
improve initial fit or even build de novo models.
After an initial model is built, refinement is
performed to maximize the agreement between the
model and experimentally observed data by
adjusting atomic coordinates, B factors and other
parameters.
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Contact Creative Biostructure Mailing Address
45-1 Ramsey Road Shirley, NY 11967, USA Email
Address contact_at_creative-biostructure.com Websi
te http//www.creative-biostructure.com/cryo-em-s
ervices_4.htm