Related Experiment Video
Updated: Apr 18, 2026

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts
Published on: December 1, 2018
Fundamental limitation of the instantaneous approximation in fold-change detection models
Maja Skataric1, Evgeni V Nikolaev2, Eduardo D Sontag3
1Department of Electrical and Computer Engineering, Rutgers University, Piscataway, NJ 08854-8019, USA.
Abstract:
The phenomenon of fold-change detection, or scale-invariance, is exhibited by a variety of sensory systems, in both bacterial and eukaryotic signalling pathways. It has been often remarked in the systems biology literature that certain systems whose output variables respond at a faster time scale than internal components give rise to an approximate scale-invariant behaviour, allowing approximate fold-change detection in stimuli. This study establishes a fundamental limitation of such a mechanism, showing that there is a minimal fold-change detection error that cannot be overcome, no matter how large the separation of time scales is. To illustrate this theoretically predicted limitation, the authors discuss two common biomolecular network motifs, an incoherent feedforward loop and a feedback system, as well as a published model of the chemotaxis signalling pathway of Dictyostelium discoideum.
Related Concept Videos
Difference from Background: Limit of Detection
The LOD indicates the presence or absence...
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
Linear Approximation in Time Domain
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length,...
Real Time RT-PCR
The real-time quantification of the number of amplified products is...
Linear Approximation in Frequency Domain
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

