One row per laboratory blank: a sterile-water control that the laboratory filtered and incubated in the same session as the field samples in samples, to detect contamination introduced by the laboratory procedure itself. A blank with zero colonies supports the validity of that session's results.
Format
A tibble with 134 rows and 7 variables
- blank_id
Unique identifier of the laboratory blank. Integer.
- date_incubation
Date on which the blank was filtered and incubation started.
- date_result
Date on which the colonies on the blank were counted and the laboratory form was submitted.
- region
Region of Uganda whose samples were analysed in the same laboratory session as the blank: Central Region, Karamoja Region, Teso Region or Busoga Region.
- district
District whose samples were analysed in the same laboratory session as the blank: Nakaseke, Kaabong, Kumi or Luuka.
- petri_dish_number
Petri dish label of the blank as written by the laboratory technician (e.g. 'B1', '12').
- ecoli_cfu
Number of E. coli colonies counted on the blank filter (sterile water processed like a sample, 100 mL). 0 indicates no contamination introduced by the laboratory procedure; 101 means more than 100 colonies (too numerous to count).