[3dem] Is there an asymmetric biological sample out there that reveals handedness at CET resolution?

[Christian Geiss]

Hello,

I am a Phd student, do cryo electron tomography and have a problem 
determining the handedness of my sample, because viewers for tomograms 
like Amira, Matlab-based scripts can invert the handedness depending if 
you look at your tomogram from top to bottom or vice versa. Since those 
programs behave to some extent like black boxes, the easiest would be to 
have a nice asymmetric biological sample where you know the handedness 
and that the latter can be judged quite easily from a reconstruction, 
meaning without further processing like subtomogram averaging.

So far, I can only think of bacterial ribosomes since they are 
asymmetric and quite big, but for cryoET the resolution would be not 
reasonable to resolve the handedness at all. Thus I could need in the 
ideal case e.g. something like a large complex that links each other to 
repetitive units with a known handedness.

I know its a tough question, but maybe someone can give creative input 
here? I would highly appreciate it!

Best regards,

C. Geiss