Compare and contrast swabs and contact (RODAC) plates for their ability to enumerate bacteria and viruses from surfaces. (Consider the question carefully, it is a bit of a trick question). Solution Swabs and contact (RODAC) plate methods are use for surface sampling for all microorganisms. In Swabs method, we use sterile cotton or calcium alginate swabs for small surfaces and Sponges for big surfaces to pick microorganisms and transfer them to broth nutrient medium. This method is easy to use, Inexpensive and can apply to any surfaces. The main disadvantage of this method is microorganisms’ recovery is very poor and collectable in broth medium only. In contact plate or RODAC plate method, the whole plate is pressed against the surface of chosen and then collect microorganisms. RODAC abbreviates for Replicate Organism Detection and Counting. This method is usable to smooth surface very efficiently and nutrient medium flexible. The main disadvantage for this method is, overgrowth occurs if surface is highly contaminated..