 Intrinsic gene-expression noise

Fluctuations due to individual random events in an expression process, conditional on shared cellular conditions. In a matched dual-reporter measurement, independent reporter fluctuations produce scatter perpendicular to the equal-expression diagonal. For mean-normalized reporters $x,y$, the intrinsic squared noise is $⟨(x-y{)}^2⟩/2$ when reporter-specific measurement noise has been accounted for.