Size and Shape Selective Metal Oxide Nanomaterials …
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severe consumer exposure thus lead to health hazards. Some examples of the effects
caused due to the risk of MONMs conducted on the mice and cellular assays could
be found in the article by Dekkers et al. and Simko et al. [57, 58].
9 Common Antibacterial Activity Assessment Methods
9.1 Plate count
The concentration of viable bacterial cells are estimated by counting colony-forming
units (CFU) before and after exposure to the MONMs. It is performed through serial
dilution of the original bacterial culture in lysogeny broth (LB) medium, taking 10
micro-litre of the serially diluted culture, subsequent spreading using sterile glass
rods onto an agar plate in triplicate and finally counting the available colonies after
incubation [59, 60].
9.2 Flow Cytometry
Heterogeneous mixtures of bacterial cells are placed in a fluid suspension and passed
through a window chamber or a small compartment in which laser scattering from the
bacterial cells gives detailed information (in a fluorescence microscope). The light
signals emitted from the suspension particles are collected and interpreted into details
such as cell morphology, nature of surface, and expressions such as intracellular
protein, gene and cellular physiology. The population of dead or live bacterial cells
is correlated by fluorescence variation from the control groups [61].
9.3 Zone of Inhibition
This test is called as Kirby-Bauer test which is a qualitative method for measuring
antibiotic resistance of MONMs solids and textiles against microbial growth [62,
63]. In this method, approximately one million bacterial cells are spread over an agar
plate and then it is incubated in the presence of the antimicrobial materials (MONMs)
loaded oxacillin disk. If the microbial strain is susceptible to the MONMs, then a
zone of inhibition will appear on the agar plate. If the strain is resistant to the said
antimicrobial agent, then no zone will appear. The thickness of the zone is measured
(using a ruler or vernier caliper) at the back of agar plate in the presence of good
illumination.
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severe consumer exposure thus lead to health hazards. Some examples of the effects
caused due to the risk of MONMs conducted on the mice and cellular assays could
be found in the article by Dekkers et al. and Simko et al. [57, 58].
9 Common Antibacterial Activity Assessment Methods
9.1 Plate count
The concentration of viable bacterial cells are estimated by counting colony-forming
units (CFU) before and after exposure to the MONMs. It is performed through serial
dilution of the original bacterial culture in lysogeny broth (LB) medium, taking 10
micro-litre of the serially diluted culture, subsequent spreading using sterile glass
rods onto an agar plate in triplicate and finally counting the available colonies after
incubation [59, 60].
9.2 Flow Cytometry
Heterogeneous mixtures of bacterial cells are placed in a fluid suspension and passed
through a window chamber or a small compartment in which laser scattering from the
bacterial cells gives detailed information (in a fluorescence microscope). The light
signals emitted from the suspension particles are collected and interpreted into details
such as cell morphology, nature of surface, and expressions such as intracellular
protein, gene and cellular physiology. The population of dead or live bacterial cells
is correlated by fluorescence variation from the control groups [61].
9.3 Zone of Inhibition
This test is called as Kirby-Bauer test which is a qualitative method for measuring
antibiotic resistance of MONMs solids and textiles against microbial growth [62,
63]. In this method, approximately one million bacterial cells are spread over an agar
plate and then it is incubated in the presence of the antimicrobial materials (MONMs)
loaded oxacillin disk. If the microbial strain is susceptible to the MONMs, then a
zone of inhibition will appear on the agar plate. If the strain is resistant to the said
antimicrobial agent, then no zone will appear. The thickness of the zone is measured
(using a ruler or vernier caliper) at the back of agar plate in the presence of good
illumination.