Visualization of inducible luciferase activity. Luciferase assay results for parental wild-type colonies and for several transformants with or without heat shock. (A) Transformants EuHR-1 and EuHR-12, generated with pHRLucP as the co-bombarded plasmid. (B) Transformants EuHsp-2 and EuHsp-11, generated with pHsp70A-GLuc as the co-bombarded plasmid. Algae cultures were divided into two aliquots; one aliquot was subjected to a heat shock at 42°C for 1 h, and the other aliquot was maintained at 27°C. Upper row: standard photo showing the assay setup. Middle row: photo without extraneous light in the darkroom following the addition of the coelenterazine substrate. Lower row: exposure to a light-sensitive film.