Median SNR' for the contaminated soil with 128 specific probes targeting the phnA2a gene. This graphic represents the detected median SNR' for each specific probe (ordered by sequence) derived from the degenerate defined probe phnA2a_MD_B targeting one particular region of phnA2a gene. Black squares: signals obtained with the model strain EPA505 with a mix of both pollutants (the highest signal is given by the specific probe targeting the strain EPA505 specific gene). Gray diamonds: signals obtained with total DNA extracted from the soil S3 (clearly showing a particular probe signature). The dotted line represents the defined threshold for SNR' values.