What is PFU per ml?

The pfu/mL result represents the number of infective particles within the sample and is based on the assumption that each plaque formed is representative of one infective virus particle.

How is titer calculated in PFU?

Example of Calculating Phage Titer The final PFU count for each plate is n × 10 × d PFU/ml, where n is the number of plaques observed and d is the value from the dilution series. This is derived from the use of 0.1 ml of the phage stock to set up the initial dilutions.

How do you calculate plaque titers?

Counting and Calculating Virus Titer Find a plate that has between 30 and 300 plaques and count the exact number of plaques on that plate. Take the number of plaques in on your plate and multiply by 10. If you counted 157 plaques, you would get 1570.

How do you calculate CFU ml?

  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 calculate PFU to particle ratio?

If we take the titer of a virus preparation (in plaque forming-units per milliliter) and divide it by  into the number of virus particles in the sample, we obtain a number known as the particle-to-PFU ratio. It is a measure of the fraction of virus particles in a given sample that can complete an infectious cycle.

What is the difference between PFU and CFU?

Plaque-forming units (PFUs) are equivalent in concept to colony-forming units (CFUs) when plating bacteria, that is, where a single bacterium, bacterial arrangement, or clump of bacteria all can give rise to only a single colony upon plating.

How do you find CFU g from CFU ml?

Multiply by 90 to get the number of colonies in the original sample, which is 900. Divide by the sample volume in ml to get CFU/ml = 100. Alternatively, if you want CFU/g, divide the CFU in the whole sample (900) by the grams of extract dissolved (1) to get 900 CFU/g.

What is a single PFU?

PFU rules out possible multiple-hit phenomena and include only the particles capable of infecting cells on their own. Thus, one PFU means one lytic event (or one infectious virus particle).