1. Obtain a 1 gram soil sample from the area to be tested. Add soil sample to 99 ml of Suspension Buffer (Catalog #IM5205), or Ringer's Solution, or it's equivalent, to give a 1:100 dilution. Thoroughly mix sample for 1-2 minutes, allow to stand 5 minutes and repeat 2 more times before proceding to next step. This step breaks up and removes particulate and facilitates recovery of bacteria for assay.

2. Add one ml of this 1:100 dilution to 99 ml of Dilution Buffer. This yields a 1:10,000 dilution. If this sample is not highly discolored, end dilution steps, otherwise repeat once more to get a 1:1 million dilution. For slightly discolored samples, control ampoules (Catalog #IM95087) are available to give a background reference color.

3. Using the final dilution, first rinse the snapping cup, then completely fill cup to the indicated level. Insert test ampoule into sample in cup and snap. Allow ampoule to fill completely before removing.

4. Incubate ampoule in a 35 ^o C/95 ^o F environment. This may be done in a shirt pocket or incubator. For shirt pocket incubation a special Carry/Incubation Tube (Catalogue #IM93357) is also available to allow safe, convenient incubation.

5. Multiply chart reading by dilution factor (10,000 or 1 million) to get final Test Result. To stop a test (incubation period), just refrigerate sample or put in an ice chest. To restart test, simply restart incubation and subtract 0.5 hour from the total cumulative time to obtain final results.

Example: Ampoule turns from yellow at start to pink at 7 hours using the 1:10,000 dilution of a 1 gram soil sample. Multiply the seven hour chart reading of 10,000 (10 ⁴ ) CFU's by the dilution factor of 10,000 (10 ⁴ ) to give a Test Result of: 10,000 x 10,000 = 100,000,000 (10 ⁸) CFU's per gram of soil.

Note: If one starts with a larger soil sample, the Test Result must be divided by the weight in grams of soil sample to get CFU's per gram of soil.