“…However, they are not always suited to pharmaceutical and medical devices due to the large difference in the number of contaminating microorganisms. Their procedures of detection may be direct, in which individual microorganisms or populations of organisms are directly observed, or indirect, whereby microbial metabolism, metabolites, or components can be Pettipher, 1983;Hutcheson et al, 1988;Rodrigues and Kroll, 1988;Rodrigues and Kroll, 1990;Diaper and Edwards, 1994;Nebe-von Caron et al, 1998;Newby, 2000;Van Poucke and Nelis, 2000;DeCory et al, 2005, electrical resistance Baynes et al, 1983Owens and WacherViveros, 1986;Silley and Forsythe, 1996;Newby, 2000 , enzyme monitoring Kroll andRodrigues, 1986;Watling and Leech, 1996;Newby, 2000 , Limulus amoebocyte lysate Jorgensen and Alexander, 1981;Bussey and Tsuji, 1984;Baines, 2000, nucleic acid probes Bauters et al, 1999Jordan, 2000;Newby, 2000;Dunsmoor et al, 2001;Jimenez et al, 2001;Serin et al, 2005;Chaieb et al, 2007;Zuluaga et al, 2009 , phage-interaction technology Wolber andGreen, 1990;Turpin et al, 1993;Stewart et al, 1996;Stewart et al, 1998;Mole et al, 1999;Wu et al, 2001 , andcarbon dioxide radiometry Cutler et al, 1989 . In addition to the methods summarized in Table 2, other techniques have been inve...…”