This powerpoint presentation begins by presenting study objectives that included the following: validation of a pectin-based agar substitute to
eliminate the need of precise temperature
monitoring for agar during assay;
validation of a method to enhance visualization of
viral plaques using a chromogenic substrate and a
dye; and,
validation of pectin-based medium using U.S. Environmental Protection Agency (USEPA)
Method 1602. Study procedures included the following: add 10 or 100 mL of water or concentrated
samples from absorption/elution method to
pectin-based medium;
add 0.75 mL bacterial stain; and,
add 3 mL log-phase E. coli culture (E. coli
Famp or CN13); add antibiotics if necessary
[Ampicillin/streptomycin when using E. coli Famp
(male-specific coliphages), Nalidixic acid when using E. coli CN-13];
swirl the bottle several times to mix well and
pour the mixture into the pretreated petri dish; allow the medium mixture to solidify on a horizontal bench
for 45 min., then turn the stacked dishes up side down quickly
and move them to an incubator (36 ± 1 ºC);
or,
immediately after pour plate, stack up the dishes and carefully
move the dishes to a leveled incubator. Plates can be
incubated in upright position. Study conclusions indicate the following: the pectin-based medium is superior to traditional agar-based
medium - results can be obtained as early as 6 hrs., easy identification by larger blue plaques with excellent
contrast, and better in recovering injured coliphages;
convenient and easy to use,
temperature control is not required and
eliminates preparation, sterilization or melting of agar medium;
field deployable; IPR and MS meets USEPA Methods 1602 QC
requirement; detection of male-specific coliphages using pectin-based medium is more sensitive than agar-based medium in filtered sewage and surface water; detection of somatic coliphages using pectin-based medium is as sensitive as agar-based medium; and,
the pectin-based medium can be used in direct membrane filtration or possible in DAL. Includes tables, figure.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.3 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 30 |
| Published : | 11/01/2009 |
