Question

You dilute your bacteriophage for plating 10^-6. You mix 0.1ml of the bacteriophage dilution with 0.3ml of bacteria and plate with top agar. The next day you count your plaques. You get 46 pfu at this dilution. What is the final concentration (pfu/ml) of the phage stock?

Answer 1

`46 * 10^7` pfu/ml

Step-by-step explanation:

Given -

Bacteriophage dilution
`= 0.1` ml

Volume of bacteria and plate with top agar
`= 0.3` ml

Number of plaques
`= 46` pfu

Dilution (d)
`= 10^(-6)`

Final concentration of phage stock is equal to

`= (pfu)/(d*v)`

Where pfu is the count of plaques

d is the dilution and v is the volume

Substituting the given values, we get -

`(46)/(10^(-6) * 10^(-1)) \\= 46 * 10^7` pfu/ml