∞ generated and posted on 2016.02.04 ∞
Means of microorganism isolation and enumeration involving mixture with molten agar that is followed by partial filling of Petri dishes.
The pour plate method can involve molten application of all of the agar subsequently found within a plate or instead application of just a thin, top layer of agar as seen with the soft agar overlay technique. Indeed, another name for the pour plate method is "agar overlay". See also spread plate method, plate count, and colony-forming unit.
Note that it is important in overlay methods to employ agar that is sufficiently warm but not too warm. A typically temperature employed is 45°C. This prevents premature solidification of the agar while at the same time, ideally, does not excessively overheat organisms. Nevertheless, one should limit the length of time that organisms are kept at this temperature and also limit the length of time that this molten agar spends at room temperature prior to pouring lest it fully or partially solidify prior to pouring.