CompactDry SL Salmonella – Shimadzu

CompactDry SL Salmonella – Shimadzu

Model: SL
Code: 54058
Manufacturer: Shimadzu – Japan

Operating Procedure

1. Sample Preparation: Aseptically weigh 25.0g of sample or pipette 25.0ml (for liquid samples) into a sterile container, such as a stomacher bag, dilution bottle, or Whirl-Pak bag.

2. Dilution & Homogenization: Add 225.0ml of diluent and homogenize the mixture. For Salmonella, use Buffered Peptone Water (BPW) or other suitable enrichment broths as per BAM guidelines.

3. Pre-enrichment: Incubate the sample at 36 ± 1°C for 20–24 hours.

4. Inoculation: * Take 0.1ml of the pre-enriched sample and dispense it onto the Salmonella plate approximately 1cm from the edge.

   • Dispense 1.0ml of sterile distilled water onto the opposite side of the plate.

   • Close the lid securely.

5. Incubation: Invert the plate and incubate according to manufacturer recommendations: 42 ± 1°C for 22 ± 2 hours.

Interpretation of Results

• Salmonella Positive (+):
  • Colony Appearance: Black or green colonies appear, either individually or in clusters.
  • Media Color Change: The surrounding medium turns yellow.

• SalmonellaNegative (-):
  • The medium color remains unchanged.
  • Colonies (if any) appear red or reddish-purple.

Notes:

• High Concentration: If the Salmonella density is extremely high, the entire plate may turn yellow without distinct individual colonies; in this case, only black or green spots may be visible.

• Disposal: After reading the results, used plates must be sterilized via autoclaving (121°C for 30 minutes) before disposal to ensure safety.