Metadata field: filtration_upper_threshold_um

Studies:

Scope: ocean, environmental

Type: numeric

Description: For ocean water and freshwater samples: upper size cutoff for the filtration during sample collection, i.e. the pre-filter pore size in µm. The contents of this filter are discarded (or at least not sequenced in this particular size fraction).

Examples: 3, 0.2, but also Infinity (when there is no pre-filtering step)

Value Count
Infinity 2863
3 406
0.2 279
5.0 275
20 210
2000 199
180 184
5 182
2.7 104
10 83
200 70
1.2 57
0.22 48
1.6 42
0.8 18
80 18
100 12
0.1 6
30 1