Method: Determine the accuracy of the z drive movement by moving with small steps through a defined 3D landscape. Z drive respositioning can also be tested by performing a short time series of 3D stacks and checking for drift. A defined 3D landscape that can be repeatedly looked at over months/years is required- an etched pattern is the best option in this case, eg Argolight or PSFCheck slide.
Justification: Accurate, reproducible movement of the stage/nosepiece is essential when rendering data in 3D and being able to accurately ascertain where objects labelled at different wavelengths are relative to one another and/or movement in time through z.
Requirements: An accurately marked slide or dish with etchings at various z depths within the same 2D field of view, e.g. Argolight or PSFCheck slide. Nyquist level stack image capture and measurement of the distances across z in software, eg ImageJ or Daybook.