Table 1. Indicative values for some experimental characteristics that are significantly different between MX and SMX where sample-decay effects might thus be expected to be markedly dissimilar.

	MX	SMX
Water content	Nearly all samples contain 50–80% water	ca 10% of all samples are hydrates or contain 1–10 molecules of crystallization. (Threlfall, 1995 ▸; Infantes et al., 2003 ▸)
Absorption cross-section at 8.05 keV (Cu Kα) and 17.997 keV	Lysozyme, 1.04 and 0.080 mm−1; Insulin, 1.02 and 0.078 mm−1	Indicative absorption coefficient for this sample: 1.736 and 0.804 mm−1
Typical incident wavelength (Å)	1.5–0.9	1.5–0.4
Typical beam size	Large range of available sizes and often adjustable	Crystal smaller than beam
Typical crystal size	3–200 µm in any dimension	20–50 µm in all dimensions
Flux in incident beam (photons s−1)	1012	1010
Applicable no. of space groups	65	230
Multiplicity due to symmetry	1–4	1–10
Molecular weight (Da)	>20000	<900
Unit-cell size / number of reflections	>50 Å axes	<50 Å axes, <5000 unique reflections, <100000 reflections per dataset
Typical diffraction limit (Å)	3.5–1.5	Beyond 0.8
No. of scans on one crystal	1 (but depends on the phasing technique used)	3–6 depending on instrument geometry