How does CENSUS-MIC work?

CENSUS is based on a revolutionary molecular microbiological method (MMM) called quantitative polymerase chain reaction (qPCR) whereby many copies of a specific gene are generated. As each gene copy is made, a fluorescent marker is released, measured, and used to quantify the number of target genes present in the sample. The gene copied during the process (target) is determined by short segments of DNA called “primers” which are added to the reaction mixture. In essence, qPCR is like a copy machine with a counter. The “primers” select which pages (target) of the book (DNA) are copied and the counter keeps a running total of how many pages were copied (number of target genes in the sample).

CENSUS Advantages

CENSUS offers many advantages over culture-based methods such as plate counts or most probable number (MPN) analyses that have traditionally been used to estimate bacterial populations in environmental samples. Traditional methods are dependent upon growth of the target microbial population on agar plates or liquid media in the laboratory. Despite advances in growth media, however, typically less than 10% and often less than 1% of the total population can be cultivated (grown) in the lab. Thus, traditional methods severely underestimate the true population.

CENSUS analysis on the other hand, utilizes DNA or RNA that is extracted directly from the sample, completely eliminating the need to grow the target organisms.

  • Accurate — DNA is extracted directly from the sample eliminating the need to grow the bacteria thus circumventing biases associated with more traditional approaches.
  • Specific — Targets either the specific bacterial group or a specific gene encoding a MIC associated metabolic process (e.g. sulfate reduction).
  • Rapid — Results are available within days (7–10 standard TAT) with rush service available.
  • Sensitivity — Practical Detection Limits (PDL) as low as 100 cells per sample with a dynamic range over seven orders of magnitude.
  • Flexibility — Analysis can be performed on a variety of sample types including water, solids/pig-runs, coupons, Bio-Traps®, and others.  Please see Sampling for details.
  • Broad Applicability — CENSUS assays can target a broad range of organisms and microbial functions.

CENSUS Approaches

CENSUS is offered in a variety of formats to meet the objectives of your particular project.

CENSUS — Are organisms present that have corrosive potential?

Our standard DNA based approach provides quantification of bacteria with the genetic potential to effect corrosion.

CENSUS-Expression — Are organisms actively expressing a desired function?

Total RNA as opposed to DNA is extracted and used to quantify metabolically active bacteria of interest that are expressing a MIC associated metabolic function (e.g. sulfate reduction).