I am requesting funds to purchase an Atomic Force Microscope (AFM) to replace an aged and failing AFM that
requires frequent major repairs. AFM is a vital method for the work proposed in the parent R35 grant which will
provide new DNA-based tools that will overcome several of the challenges associated with MP structure deter-
mination by single-molecule cryo EM.
An AFM is needed for the development phase of our DNA-lipid nanodiscs, as AFMs produce images of individual
particles with a higher resolution, contrast and signal to noise ratio than other imaging methods and no other
method provides topographical information. Instant access to this instrument in our laboratory avoids long wait
times thus shortening the cycles of iterative improvements of our DNA-based tools. AFM sample preparation is
also much faster and requires less material than TEM grid sample preparations while avoiding staining, drying
and transfer into a vacuum. In AFM, samples are imaged in native buffers, instead. The new instrument supports
imaging with video frame rates which would allow us to study dynamic processes including nanodisc fusion and
lipid exchange. Moreover, the accelerated imaging dramatically reduces the time that is required to image a
statistically relevant number of particles which is needed for a biophysical quantification of structural parameters
and synthesis yields of the DNA rings. Finally, the requested instrument will be the first modern AFM on the
campus and I therefore expect interesting collaboration requests that will leverage our expertise in AFM.