GUS Assay in Plants

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GUS Assay in Plants Inquiry

GUS staining is a very powerful tool in plant molecular biology, delivers great versatility for various applications (1). As a sensitive and reliable method that is also easy to perform, GUS staining has become the most popular way to evaluate gene expression in plants.

GUS is short for β-Glucuronidase, a gene from Escherichia coli (E.coli) that encodes a sugar consuming enzyme–Glucuronidase. As there is no detectable GUS gene expression in plants, and the bacterial GUS gene does not interfere with plant intrinsic gene expressions, GUS provides an ideal reporter, being orthogonal to native genetic machinery, for gene expression in the plant system. By fusing the promoter of genes of interest to the GUS coding region, the expression patterns of plant genes can be reflected by the activation of GUS.

With years of experience of plant molecular biotechnology, Lifeasible provides high quality services for GUS staining with a wide range of plant materials (suspension cells, protoplasts, callus, plant organs and whole plants). Adapting to differential research purposes from each project, we offer multiple substrates for both GUS histochemical assay and GUS fluorimetric assay (2), with optimized experimental buffers and protocols.  

  • GUS Histochemical assay: for examination of the expression location and expression pattern of specific genes.

    • Substrate: 5-bromo-4-chloro-3-indolyl glucuronide (X-Gluc), which gives an insoluble indigo-blue precipitate at the site of GUS activity (Figure 1).

Figure 1. The GUS staining assay of Arabidopsis ACC synthase genes (3).

  • GUS Fluorimetric assay: for quantitative measurement of gene expressions. The fluorimetric signal is detected by a spectrofluorometer for high sensitivity quantification
    • Substrate: (1) 4-methylumbelliferyl-β-D-glucuronide (MUG), which gives fluorescence emission at the site of GUS activity. (2) 4- trifluoromethylumbelliferyl-β-D-glucuronic acid (4-TFMUG), substrate with improved fluorescence properties, including enhanced fluorescence intensity, less background and longer endurance.

As a leading plant biotechnology company with robust technical establishments, Lifeasible proudly offers one-stop services that cover every step of plant GUS staining assays, including:

  • Molecular cloning, chimeric gene construction
  • Cell/tissue/whole plant transformation
  • Sample collection and preparation
  • GUS staining
  • Tissue fixation
  • Sample imaging/fluorescence detection
  • Image analysis/total protein quantification
  • Data organization and reporting

Meanwhile, plant scientists and experts from both Lifeasible and our distinguished collaborators worldwide will work closely with the clients to ensure that sufficient intellectual and technical assistance is given to each project. Together, we guarantee the quality and success of your research work.


  1. Jefferson RA, Kavanagh TA, & Bevan MW (1987) GUS fusions: beta-glucuronidase as a sensitive and versatile gene fusion marker in higher plants. EMBO J 6(13):3901-3907.
  2. Cervera M (2005) Histochemical and fluorometric assays for uidA (GUS) gene detection. Methods Mol Biol 286:203-214.
  3. Wang NN, Shih MC, & Li N (2005) The GUS reporter-aided analysis of the promoter activities of Arabidopsis ACC synthase genes AtACS4, AtACS5, and AtACS7 induced by hormones and stresses. J Exp Bot 56(413):909-920.