How to characterize the Limit of Blank for digital PCR?
Why calculate a LOB in digital PCR?
In digital PCR (dPCR) false-positive events can arise from several sources of molecular biology noise. Determining a false positive cutoff when quantifying nucleic acids is therefore critical to the robustness of a dPCR assay. To define this cutoff, detection thresholds are commonly set above the Limit of Blank (LOB) value that must first be determined for each target during assay calibration.
We recommend the application of this LOB decision tree as a good practice before any new assay, particularly when a target is expected in low concentrations. Furthermore, the experimental LOB value is necessary both to determine if a reaction is positive or negative and to calculate the theoretical Limit of Detection (LOD).