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How do we quantify microorganisms?

The technique we use for Q-Bioanalyses is called Quantitative Polymerase Chain Reaction (Q-PCR). It is a technique we have been using for the past 10 years which enables us to detect and quantify microorganisms based on distinguishing features on their genetic material: DNA and/or RNA (a measure for activity).


We use the Q-PCR method within our consultancy and research projects as it gives us accurate and quantitative results (it can distinguish between 1 and 1.0x1012 (1 trillion) microorganisms without the need to dilute a sample). The method is also suitable for routine monitoring of processes and therefore enables us to accurately follow a microbial process in time. Over the years we noticed that our analyses were also of value to third parties which is why we now offer them as separate labservices to anyone who has the need to gain insight and/or control over microbiology.

Traditionally detection of microorganisms is based on growing them on selective growth substrates. This includes methods based on colony forming units (cfu), most probable numbers (MPN) or visual determination of, for example, colour changes. However, these methods have a number of drawbacks. Most importantly that many micro-organisms cannot be cultured under synthetic circumstances as the required growth conditions are unknown or cannot be reproduced. The percentage of micro-organisms that can be grown depends on the complexity of the sample and is usually estimated to be less than 1%!

Q-PCR is culture-independent and therefore enables micro-organisms to be found that will otherwise remain 'unseen'. The quantitative results are determined online and do not rely on interpretation based on visual observations or counting. Internal quality controls are included in all our Q-PCR analyses. That is why we use Q-PCR.