Rep 1: 275 Rep 2: 250 Rep 3: 200 Avg: 241.6 SE: Using the following formula, det
ID: 135400 • Letter: R
Question
Rep 1: 275
Rep 2: 250
Rep 3: 200
Avg: 241.6
SE:
Using the following formula, determine the number of bacteria m-3 air sampled based on the average number colonies calculated in step B: Calculate the number of colonies collected l-1 of air; bacteria density m-3 air =AVE×SOL/(INOC × AIR), where AVE is the average number of colonies on the three replicate plates; INOC is the volume of inoculated (or filtered) solution, in ml (e.g. 0.1 ml is 100 ?l); SOL is the total volume of solution in which you suspended the slide; AIR is the volume of air (m3) collected during the sampling (note: 1000 l = 1 m3). Show your work here:
Explanation / Answer
Ans :
SOL is the total volume of solution in which you suspended the slide? This data is not given but I have considered it as 1L
bacteria density m-3 air =AVE×SOL/(INOC × AIR)
AVE = 241.6,
SOL =1L?,
INOC = 0.1 ml = 0.0001L
AIR = 1m3 = 1000L.
=241.6x 1L/ (0.0001L x1000L) = 241.6 / (0.1) = 2416 bacteria in 1 m3 air