Biomedical Engineering Reference
In-Depth Information
•. MMNs.(200.mg).were.suspended.in.50.ml.of.sterile.deionized.water.(4.mg/ml),.and.
200.μl.of.the.MMN.suspension.was.added.to.each.diluted.grey.water.tube..Then.
four. replicates. of. the. previous. mixtures. were. prepared. at. different. incubation.
times.(10,.20,.30,.and.40.min).to.evaluate.the.sensitivity.of.the.time.in.this.assay,.
and.incubated.with.shaking.incubator.at.37°C.
•. A.magnet.(400.G).was.placed.on.the.bottom.side.of.each.tube.for.20.min,.the.super-
natant. was. removed. (while. the. magnet. was. still. on). and. transferred. into. other.
sterile.tubes,.and.the.pellet.was.washed.by.sterile.deionized.water.
•. Serial.dilution.for.each.tube.of.supernatant.and.pellet.was.done;.0.1.ml.from.differ-
ent.dilutions.was.inoculated.in.nutrient.agar.and.EMB.agar.plates.and.incubated.
for.24.h.at.37°C..Then.the.total.heterotrophic.aerobic.bacterial.and.total.coliform.
counts.(cfu/ml).were.recorded.as.before.(see.Table 17.3).
17.2.11 Transmission Electron Microscopy Sectioning and Imaging
•. One.milliliter.of.diluted.MMN.suspension.was.placed.into.200.μl.of.freshly.pre-
pared.
Salmonella
.bacterial.suspension.and.incubated.for.30.min.in.a.shaker.incu-
bator.at.37°C.
•. Also,.a.mixture.of.1.ml.of.the.MMN.suspension.and.200.μl.of.the.
Salmonella
.sus-
pension.was.incubated.overnight.in.a.shaker.incubator.at.37°C.
•. A.freshly.prepared.bacterial.sample.(alone).was.used.as.a.negative.control.
•. The. three. samples. above. were. ixed. overnight. using. special. ixative,. and. dehy-
drated.in.ethanol.or.acetone.before.being.embedded.in.EPON.resin.overnight.
•. The. prepared. samples. were. sectioned. using. an. ultramicrotome,. and. examined.
under. a. transmission. electron. microscope. to. reveal. the. inside. of. bacterial. cells.
(Figure 17.6).
MMN
(a)
(b)
(c)
FIGURE 17.6
Sections. of.
Salmonella
bacterial. cells. when. mixed. with. MMNs. as. viewed. under. a. TEM.. Arrows. indicate. the.
penetration.of.MMNs.inside.bacterial.cells.
