Skip to content

Structural Biology Unit

Octamer from the Structural Biology Lab

About our work

The Structural Biology Unit is part of the Biological Imaging Core Facility.

The Structural Biology Unit is located in building 6 room 206 on the NIH main campus.  Dr. Vatsala Sagar oversees operation of this facility whose main focus is crystallography and CryoEM. For crystallization projects, the lab has access to a Mosquito crystallization robot, a MUVIS tryptophan fluorescence microscope and access to the APS synchrotron. The SBU also has an array of 96 well crystallization screens to determine optimal conditions for crystallization with only 1mg of protein. We also have access to a CryoEM facility for CryoEM structure determination.



  • Modeling of protein structure using RoseTTAFold or AlphaFold
  • Design of constructs suitable for crystallization
  • Design and optimization of protein purification protocols to obtain 99% pure protein using FPLC and affinity, ion exchange and gel chromatography
  • 96 well crystal screening using Mosquito robot
  • Collection of diffraction data at APS synchrotron
  • Atomic level structure determination using molecular replacement or SAD
  • Structural analysis using Pymol or Chimera


  • Design of constructs suitable for CryoEM
  • Grid preparation for negative stain
  • Frozen grid preparation for CryoEM by Leica Autoplunger
  • Optimization of sample grid preparation
  • Collection of initial CryoEM data
  • Shipping crystals to the Stanford-SLAC CryoEM Center and collection of high resolution data on Krios


Structural Biology Unit key staff

Key staff table
Name Title Email Phone
Vatsala Sagar, Ph.D. Unit Chief 301-402-8649

Last updated: March 1, 2023