Fig. 4.

Microscopic images of biofilm matrix and cell aggregate of P. aeruginosa strain PA14. (A) Brightfield image of the microreactors grown in vitro for 24 h. (B) SYPRO® Ruby staining of biofilm matrix in red. (C) FM® 1–43 staining of cells within the microreactors in orange. (D) Co-registered image of two stains showing microbes embedded in biofilm matrix. Scale bar as indicated. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)