Table 2. Comparison of methods for delivering crystals into the X-ray beam for room-temperature crystallography, based on their current state of development.

Background-scatter evaluation assumes, for fixed-target approaches, that excess liquid around crystals has been minimized by blotting or suction. For alternative comparisons of these methods, see Table 1 in Cheng (2020 ▸) and Table 1 in Martiel et al. (2019 ▸).

Sample-delivery method	No. of crystals	Crystal size range	Crystal targeting	Data-collection modes	Total volume of crystals probed by X-rays (%)	Background scatter	T = 100 K and multi-T data collection?
Fixed targets
Glass capillary	1–∼10	<2 mm	Center on each crystal; raster	Full (360°) oscillation; helical scanning	∼100%	High	Maybe
Loop/mesh + polymer capillary	1–∼102	<1 mm	Center on each crystal; raster	Full oscillation; helical scanning	∼100%	Moderate	Yes
Loop/mesh + humidified gas stream	1–∼102	<1 mm	Center on each crystal; raster	Full oscillation; helical scanning	∼100%	Low	Yes
Solid support with array of holes/wells/windows
Small area/HT MX compatible	1–∼104	<hole size (∼10–20 µm)	Step and repeat	Partial oscillation (∼10–90°)	0.1–10%	Low	Yes
Large area	1–∼106	<hole size (∼10–20 µm)	Step and repeat	Fixed orientation	0.1–10%	Low	No
X-ray transparent support (polymer, SiN)
Small area/HT MX compatible	1–∼104	<2 mm	Center on each crystal; raster	Nearly full oscillation; helical scanning	∼100%	Low	Yes
Large area	1–∼106	<2 mm	Center on each crystal; raster	Fixed orientation	∼100%	Low	No
Jets, streams, tape
Liquid jets	>109	<jet diameter (<10 µm)	Jet moves through beam at ∼30 m s−1	Fixed orientation	<0.01%	Low	No
LCP and LVE injector streams	>106	<gel diameter (<30 µm)	Gel moves through beam at mm s−1	Fixed orientation	<1%	Moderate	No
Drop-on-tape	>106	<drop diameter (<200 µm)	Drops move through beam at mm s−1	Fixed orientation	<0.1%	Moderate	Maybe