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ROCK IMAGER User's Guide | Chapter 15: FAQs
What platforms is SONICC compatible with?
All optically assessable platforms are compatible.
Will the laser damage my crystals?
Preliminary experiments show no detectable damage to protein crystals. In one experiment, a protein
crystal was imaged on one half with excessive laser input. X-ray diffraction was obtained from both
the exposed and un-exposed halves of the crystals. Both sides diffracted to within expected resolution
(~2 A) and within statistical variation (i.e. there was no statistical difference between the diffraction of
both sides). SONICC has also been utilized to image live cells with no observed impact (they remained
adhered to a Poly-Lysine coated slide).
Can I still use SONICC if my sample is fluorescent?
Yes, as long as the fluorescence is stokes shifted by 10 nm, then it will not be detected or interfere
with the SHG.
Can SONICC be used to detect crystal quality?
Unfortunately, as of yet it can not, but we are looking into means of assessing quality based on
polarization changes of the emitted light.
Specifications
How small of a crystal can SONICC detect?
Theoretically the lower limit of detection can be estimated by the forward to backward ratio of the
SHG. Based on the coherence length of the generated SHG and the refractive index of the material
this lower limit ranges from 90 nm – 300 nm in thickness. In practice, crystals of the size of 1 µ
m3
can
routinely be detected. 2-D crystals have also been routinely imaged with S/N > 30.
What is the spatial resolution?
Dependent on the field of view being imaged, pixel sizes range from 0.5 µm to 3.5 µm. The spot size
of the laser is 3.5 µm for the large field of view objective, and 1.5 µm for the highest magnification.
What is the z resolution and how deep can it penetrate?
The laser focuses to a width of 50 um – 10 µm (depending ob the objective) and can image drops
greater than 3 mm tall with multiple z-steps.
How fast is SONICC?
The current electronic package allows for 512 x 512 image acquisition for one z-slice in 500 ms. This
corresponds to 8 traces of the fast scanning mirror per line. A one drop 96 well plate can be imaged
with SHG in 15 minutes with 8 z-slices and 5 minutes for visible imaging.
