| Swab method | - used mostly on areas with uneven surfaces; cracks, corners, crevices, depressions, elbow joints
- sterile cotton or calcium alginate swabs
- flat area exposed by template is swabbed
- inoculated swab placed in suitable diluent
- vortexted to release microbes
- SPC performed on inoculated diluent |
| Swab method: diluents | Cotton swabs: 0.1% peptone, buffered peptone water, 0.85% saline
Calcium alginate swabs soluble in: 1% sodium citrate, sodium glycerophosphate, sodium hexametaphosphate |
| Contact Plate Method (RODAC Method) | - Replicate Organism Detection and Counting
- used on smooth surfaces
- best for cleaned & sanitized surfaces
- highly contaminated surface --> overgrowth on agar plate
- randomize selection of sampling sites
- add neutralizers to agar to neutralize chemical sanitizer residues
- plate with raised sterile agar medium
- exposed agar pressed to flat surface
- inoculated agar covered and incubated
- bacterial colonies counted |
