Comparison of enumeration of bacterial cells from surface water, tap water, and Milli-Q water by the ScanRDI by using SG and ChemChrome staining to enumeration of bacterial cells by plate counts on R2A agar (n = 2 to 3). Symbols: black circles, esterase surface water; gray circles, SYBR Green surface water; open circles, SYBR Green surface water after formalin fixation; black squares, esterase tap water; gray squares, SYBR Green tap water; open squares, SYBR Green tap water after formalin fixation; black triangles, esterase Milli-Q; gray triangles, SYBR Green Milli-Q; open triangles, SYBR Green Milli-Q after formalin fixation. The diagonal line is the line of equality.