Probability assay I

ParameterValue for indicated portion of log phase
Cell concn (cells/ml)a2 × 1062 × 1071 × 108
No. of tubes with motile spirochetes233636
No. of tubes with nonmotile spirochetes37140
No. of tubes with motile spirochetes/total no. of tubes23/6036/5036/36
% of tubes with motile spirochetes3872100
Statistical significance (chi-squared with Yates's continuity correction)Early vs mid, P = 0.000857Mid vs late, P = 0.00154Early vs late, P = 6.89 × 109
  • a Concentration to which cells were diluted.