Thursday 22 December 2016

Anderson Positive Hole Conversion

  •  Is called most probability number or microscope method.
  • 2 spores can grow on one cfu.
  • Microorganisms are merged at an impaction site to a produce a single colony.
  • Sampling unit collected cells multiply in to colonies.
  • Quantitative data
  • Many discrete entries easily detected but difficult to count.
  • Viable particles to the petriplate and conversion to this count to a particle count by use of positive hole conversion.
Role:
  • Number of the viable particles being impinged on probability of the next particle going into an "empty hole" decreases
.      Ex : 2 CFU
                  = 380 (1/380 + 1/(380-1) + 1/(380-2) + 1/(380-2+1)
                        = 380 X 0.00263 + 0.00263 + 0.00264---------------+ 0.00265
                        = 380 X 0.01055
                        =4.009

    1---------------3
    2---------------4



What is the fumigation and fogging?

What is the fumigation and fogging?