Exercise 4: Environmental sampling

Question 1

What is a RODAC plate?

Answer 1

The RODAC plate is a special plate in which the agar has been slightly overfilled due to a higher concentration of agar in the medium preparation. When the cover is removed, it can be seen that the agar surface protrudes slightly above the lip of the plate, providing a convex surface.

Question 2

What is a swab technique or swab contact method?

Answer 2

A sterile swab is moistened with a special phosphate buffer diluent solution and is then used to wipe a defined area on objects or surfaces. The swab is then returned to the vial containing the diluting fluid, tightly capped, and transported back to the laboratory.

Question 3

What is acceptable sanitation?

Answer 3

Acceptable sanitation is defined by samples that have not more than 100 colonies.

Question 4

What technique must you multiply by 10 for every colony seen?

Answer 4

The swab contact method since it was only a .1 ml sample and standard is 1ml.