Multiple-Tube Method 95%Confidence Limits Combination MPN Index/ of Positives 100 ml Lower Upper 42-0 22 9 56 4-2-1 262 12 65 43-0 12 6 4-3-1 33 1 1 4-4-0 34 16 80 5-0-0 23 9 86 5-0-1 10 110 5-0-2 40 20 140 5-1-0 10 120 5-1-1 50 20 150 5-1-2 30 180 5-2-0 50 20 170 5-2-1 30 210 5-2-2 9 40 250 5-3-0 80 30 250 5-3-1 110 40 300 5-3-2 140 60 360 (b)MPN table Figure 6.18b Multiple-Tube Method Figure 6.18b