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Table 1 System used to grade biofilm formation

From: Biofilm formation on three different endotracheal tubes: a prospective clinical trial

Biofilm
coverage
Biofilm density Biofilm thickness scale Biofilm grade
Determined at 100× to 1000× mag Determined at 10,000× to 30,000× mag Determined at 10,000× to 50,000× mag (coverage + density + thickness)
0 no biofilm
1 scarce (<  10% coverage)
2 clusters (10–70% coverage)
3 confluent (>  70% coverage)
0 no biofilm
1 low/very porous
2 intermediate
3 high/compact
0 no biofilm
1 thin (0.1–1.0 mm)
2 medium (1.1–7 mm)
3 thick (> 7 mm)
0 no biofilm
1–3 low grade
4–6 medium grade
7–9 high grade
  1. The biofilm grade was calculated by adding together the scores for biofilm coverage, density, and thickness. Mag magnification