There are many advantages to using 3M Petrifilms. If properly refrigerated and sealed. Petrifilm has a long shelf life. Films are stackable and take up less space than agar plates in the incubator. Petrifilm techniques are user friendly and versatile.
Experimental results are very reliable if standard laboratory procedures are followed.
The slightly higher purchase cost of Petrifilm is offset by the time saved in preparation and reliability of the product. Agar plates require several hours to sterilize and assemble. Most schools do not have effective sterilization equipment and most teachers do not have the necessary preparation time. Disposal of Petrifilm requires only a small amount of bleach and a sealed plastic bag. Bacteria growth on Petrifilm can be further studied in the same ways as bacteria grown on traditional media.