a and b: E. coli DH10B cells devoid of SHV β-lactamase stained with anti-SHV FLABs. c and d: detection of periplasmic SHV β-lactamase in a K. pneumoniae clinical isolate possessing the SHV-5 β-lactamase. e and f: visualization of SHV-1 β-lactamase in a laboratory strain of E. coli expressing SHV-1. Microscopic magnification is 1000×. Figure 1b, 1d, and 1f are enlarged images.