Patent ID: 8563265

Claim:
A method for evaluating microbial contamination of an object, comprising the steps of: (a) incubating a sample taken from the object starting at time t o , (b) periodically ascertaining an O 2 concentration of the incubating sample until the detected O 2 concentration decreases below a threshold value, (c) establishing the time period t Threshold measured from t o to the time at which the O 2 concentration decreased below the threshold value, and (d) correlating t Threshold to a viable aerobic microbe count in the sample prior to incubation, utilizing the linear equation: y=mx+b (Eq. 1) wherein: x=logarithm of the viable aerobic microbe count per unit weight of, volume of or area swabbed to obtain a sample at t o y=t Threshold x-intercept=(−b/m)=an estimated or experimental value for the logarithm of the minimum viable aerobic microbe count at t o in a sample effective for causing the sample to reach t Threshold substantially instantaneously upon commencement of incubation, and m (slope)=( y 2 −y l )/( x 2 −x 1 ) wherein: x 1 and y l are ascertained experimentally by establishing t Threshold for a sample taken from an object having a known x, and x 2 and y 2 are values of x and y at the x-intercept (−b/m, 0).