Escherichia colihisDegfp

What does GFP measure in a ΔhisD biosensor?

Change

hisD deletion; separate chromosomal EGFP labeling.

Measured

Growth by OD600 and an introduced EGFP signal in relative fluorescence units.

Observed outcome

BW25113-derived JW2002 is the ΔhisD histidine auxotroph. Its growth required supplied histidine in the tested minimal media.

Source 1

System: Escherichia coli · BW25113-derived JW2002 ΔhisD with a separate EGFP reporter
Setting: Minimal-medium amino-acid biosensor study.
Comparison: The biosensor with focal amino acid, without amino acids, or with other amino acids.

What was observed

Checked findings go into your research brief.

ObservedSource 1

BW25113-derived JW2002 is the ΔhisD histidine auxotroph. Its growth required supplied histidine in the tested minimal media.

Table 1, JW2002 row; Results: Verification of auxotrophy; Figure 1

ObservedSource 1

The ΔhisD biosensor was separately labeled with chromosomal EGFP; fluorescence was not a native hisD product.

Construction of EGFP-labeled amino acid biosensors

ObservedSource 1

The EGFP-labeled ΔhisD histidine biosensor had a reported linear growth response over 0.5–10 µM histidine; Figure 2 reports four replicates and 95% confidence intervals.

Results: Amino acid-dependent growth; Figure 2 caption

Measurement details

Reported value: 0.5–10 µM histidine
Group: Histidine biosensor calibration
Replicates: Replicates as reported; not labeled independent biological replicates

What this supports

Interpretation

The reporter reads growth under the assay conditions.

What this does not establish

hisD deletion alone does not create green cells.

Gene location & edit specificity

No exact edit interval established by this evidence review.

hisD · BW25113 parent reference

Sources

Reviewed Sep 26, 2026

1Design and Characterization of Auxotrophy-Based Amino Acid Biosensors2012 · Peer-reviewed experiment

Reviewed: Selected full-text sections
Sections: Table 1 · Figures 1–2 and captions · Construction of EGFP-labeled amino acid biosensors · Verification of auxotrophy · Amino acid-dependent growth of the biosensors
DOI: 10.1371/journal.pone.0041349

was introduced into the chromosome of the obtained biosensors

Introduction, paragraph describing EGFP labeling

Read the source