! Although this method could give a 95% confidence limit of the count, it may
not always be practical or possible because only those plates that contain
between 25-250 colonies can be used, this means that you need to have
several plates to count to obtain the 95% confidence limit.
! The media used in counting may not contain sufficient nutrients to allow
organisms in the sample to grow.
! Injured cells may not grow and produce colonies within 48 hours.
! Considerable time and materials are required for analysis of a sample.
! Inherent variations in the procedure can lead to erroneous result