Do you need to know, the aggregation state of a protein or the stoichiometry of a protein complex ?

Can we help? Our scanning transmission electron microscope is calibrated and routinely employed to measure the mass of biological samples from their electron scattering power.

Advantages:

• Only a small amount of sample is required.
• Measurements can be made over a large mass range.
• Provides an image of the sample which allows visual assessment and also mass mapping in some cases.

• Mass of particles: 100 kDa to over 25 MDa.
• Mass-per-length of filaments: 2 kDa/nm to over 130 kDa/nm.
• Mass-per-area of layers: approx. 1 kDa/nm² upwards.

• ± 5 - 10 %; limited by the sample.

Can be in their usual buffer solution. High concentrations of metallic cations, sucrose and glycerol should be avoided if possible.
A protein concentration of 1 µg/microscope grid is generally sufficient (particles). In all, 4 to 8 grids prepared using 7.5 µl of solution are required to optimise the sample concentration and make the measurements.

Dr. Shirley Müller
 or
Prof. Andreas Engel

M.E. Müller Institute (MSB)
Biozentrum
University of Basel
Klingelbergstr. 70
CH-4056 Basel, Switzerland
Phone: +41-61-267 2254
Fax: +41-61-267 2109