Services and Training

The BCBP cryo-EM team can offer advice to help you in sample preparation for successful cryo-EM studies. Our staff has expertise in the preparation of both soluble as well as membrane proteins, preparation of nanodiscs, and peptidiscs for the difficult-to-vitrify membrane proteins and will be able to provide help in moving your projects faster.

Our recommendations for protein samples to increase the chance of success in cryo-EM are:
Amount of protein – 50 -100 microliters of protein at 0.5 – 5.0 mg/ml

Molecular weight of protein – Lower limit: ~50-60 kDa.

A single clear band in Coomassie-blue stained SDS-PAGE (recommended).

A sharp peak in a suitable SEC column and/or uniformed size in dynamic light scattering, MALS or mass-photometry.

Your samples will be vitrified on a grid of the user’s choice (Quantifoil or C-flat, gold or copper, with or without support such as 2nm thick carbon film or suspended monolayer graphene) using a Vitrobot Mark IV (a semi-automatic plunger) in a humidity-controlled room. Grids will be prepared under different conditions (blotting time, sample concentration, and/or plunging force) to assess the best conditions for data collection.

Grids will be screened using a Krios cryo-electron microscope equipped with a Gatan K3 Direct Electron Detector to ensure that single-particle studies, cryo-ET, or microcrystal electron diffraction can be conducted optimally. Areas on grids will be prioritized for full high-resolution data collection. For single particle analysis, we will determine grid properties including ice thickness, particle density, and particle distribution. Grid screening can be combined with overnight data collection.

Our expertise in cryo-EM services can help users in analyzing their data using cisTEM, RELION, and or cryoSPARC and determine structures.

Our Krios G4 cryo-TEM is equipped with the Gatan K3 camera loaded with a Gatan Imaging Filter (GIF) to provide best-in-class cryo-electron tomography data. A Volta Phase plate can be used to improve the contrast in tomograms. 

Our Krios G4 cryo-TEM is equipped with the Thermo Scientific CETA-D Camera, and Thermo Scientific EPU-D™ software for screening micro-crystals, and automated data acquisition. Our expert team can analyze the data and perform the structural determination.