Table 2. Summary of the major detection, positioning or centring techniques on the beamline.

Technique	Spatial resolution achieved	Time	Expense	Outcome
Optical microscopy	∼2 µm	Rapid	Medium	For visible crystals the crystal can be centered accurately.
UV fluorescence	∼2 µm	Rapid	Medium	If the crystal fluoresces it can be centered accurately.
Visible two-photon fluorescence	∼2 µm			Similar to UV.
SONICC	∼2 µm	Medium	Very high	Similar to UV.
X-ray rastering	Sensitive to the diffraction properties despite the size (depends on the smallest available X-ray beam size)	Short	High	Not only can the crystal be centered but the spatial diffraction properties can be characterized.