What is viable plate count method?

The viable plate count, or simply plate count, is a count of viable or live cells. It is based on the principle that viable cells replicate and give rise to visible colonies when incubated under suitable conditions for the specimen. (OpenStax CNX, 2018) A measured amount of a liquid culture is inoculated onto a plate.

What is the advantage of viable count method?

Despite its shortcomings, the viable plate count is a popular method for determining cell number. The technique is sensitive and has the advantage of only counting living bacteria, which is often the important issue. Any concentration of microorganism can be easily counted, if the appropriate dilution is plated.

What is the difference between total count and viable count?

The main difference between the two is that total count determines the count of all cells both dead and alive while viable count estimate the number of viable or live cells only capable of growing into distinct colonies.

How is cfu count calculated?

1. To find out the number of CFU/ ml in the original sample, the number of colony forming units on the countable plate is multiplied by 1/FDF. This takes into account all of the dilution of the original sample.
2. 200 CFU x 1/1/4000 = 200 CFU x 4000 = 800000 CFU/ml = 8 x 10.
3. CFU/ml in the original sample.

How do you count in Neubauer chamber?

Lets calculate total WBC count by using Neubauer counting chamber.

1. Number of cells counted = N = 150 (suppose)
2. Area Counted = 1 mm2 x 4 = 4 mm2 (area of four large corner squares)
3. Depth = 1/10 mm.
4. Dilution = 1:20.
5. Hence WBC/Cubic mm of Whole Blood = N x 50 = 150 x 50 = 7,500.

Why is CFU used in viable count?

The CFU method has two noteworthy advantages, namely the capacity for counts of any number of bacteria using dilutions, if too many, or concentrations if too few. Second, only viable bacteria are counted with this method as the CFU method excludes dead bacteria and debris.

What is CFU counting?

A colony-forming unit (CFU, cfu, Cfu) is a unit used in microbiology. It estimates the number of bacteria or fungal cells in a sample which are viable, able to multiply via binary fission under the controlled conditions.

How many cells are in CFU?

While doing this you are assuming that one cell will form one colony. But you don’t know, may be 2 or 3 cells form one colony. Since you are not sure than you express the number as colony forming units or cfu per ml. the forming unit can be one cell or more.

What CFU means?

Colony-Forming Unit
A CFU is defined as a single, viable propagule that produces a single colony (a population of the cells visible to the naked eye) on an appropriate semisolid growth medium.

What is a viable count in microbiology?

A viable cell count allows one to identify the number of actively growing/dividing cells in a sample. The plate count method or spread plate relies on bacteria growing a colony on a nutrient medium. The colony becomes visible to the naked eye and the number of colonies on a plate can be counted.

What is Neubauer ruling?

Neubauer Ruling The number of cells per cubic millimeter = Number of cells counted per square millimeter X dilution (if used) X 10. The number of cells per milliliter = Number of cells counted per square millimeter X dilution (if used) X 10,000. One (1) Milliliter = 1000 cubic millimeters (cu mm)

How many cells is a CFU?