Quantitative β-glucuronidase assay in transgenic plants

Several factors influencing reliability of the quantitative fluorimetric β-glucuronidase (GUS) assay in transgenic plant tissue have been investigated. We obtained linear dependence of fluorescence on both the duration of hydrolysis and the extract concentration. The stability of the enzyme in the homogenate was fairly high, the same as the stability of the substrate solution and of the final reaction product. The modification of the extraction/incubation buffer was proposed, resulting in several times higher activity in comparison with original procedure.