Guard cell isolation techniques.

Optical microscope images of different methods used in attempting to isolate guard cells (GCs) from Vicia faba. The processes include: (a) epidermal peeling; (b) blending and filtering; (c) blending, filtering, and probe sonication; (d) blending, filtering, and digesting with Driselase; and (e) blending, filtering, digesting with Driselase, filtering (50 μm), and probe sonication. (f) An isolated GC of greater magnification, showing fully intact, spherical chloroplasts is also shown. Isolated GCs are circled. In all cases, except where specified, the filter size was 210 μm, enzyme digestion time was 60 min, and probe sonication was performed at 60 amps for 60 sec.