Probing Intercell Variability Using Bulk Measurements.

Area of Science:

• Synthetic biology
• Systems biology
• Biophysical chemistry

Background:

• Accurate measurement of noise is crucial for synthetic biological system design and function.
• Single-cell measurement techniques (e.g., flow cytometry, fluorescent microscopy) quantify cell-to-cell variability but are costly and not high-throughput.
• Plate-reader devices are common for high-throughput experiments, necessitating methods compatible with bulk measurements.

Purpose of the Study:

• To develop novel reporter systems for estimating cell-to-cell variability in synthetic biological systems using only bulk measurements.
• To provide a cost-effective and high-throughput compatible method for assessing biological system output variability.
• To analyze the feasibility and performance of reporter systems based on FRET and sRNA circuits.

Main Methods:

• Described reporter systems enabling cell-to-cell variability estimation from bulk cell culture properties.
• Analyzed a fluorescent protein Förster Resonance Energy Transfer (FRET) reporter pair system.
• Investigated an alternative reporter system based on an activating small regulatory RNA (sRNA) circuit.

Main Results:

• The FRET-based reporter system reliably estimates variability with typical literature parameters.
• The feasible parameter space for reporter system function was assessed.
• The reporter system's performance dependence on extrinsic and intrinsic noise was investigated.

Conclusions:

• Novel reporter systems can be experimentally realized for measuring synthetic gene circuit output and intrapopulation variability.
• These systems offer a low-cost solution for high-throughput assessment of cell-to-cell variability.
• The developed reporters facilitate a deeper understanding of noise in synthetic biological systems.