Question

data given

Procedure for Serial Dilutions: Experimental Data is given II ml 1 ml ml ml I ml Tube 11 Tube 21 Tube 3 Tube 4 Il ml 1 ml ml No of bacterial Colonies TNTC TNTC 290 35

Answer 1

we - Serial dilution is used to reduce the concentration of cells in a dense bacterial culture. As go on increasing dilution the number of I goes on U decreasing because of increase in dilution factor. To perform the colony count we can choose a blate that has between 30-300 colonics More than 300 colonies present an overcrowded plate and hence we say that the colonies are Tio numerous to count CINTC). Caleny count using these plates will yield erroneous results as overcrowded bläks will have clumped or merged colonies. Less than 30 bacteñal colonies is called TFTC (Too few to Count). Such a small count could also yield erroncous results even it there is small error in dilution. So TNTG condition is not ideal for colony counting because you just can't count the clumped Clones I and similarly TFTC is not reliable for colony counting a - In your exfperiment you can use the plate with dilution factor loo at has 2 90 Colonies. You can also use blanke having colony count between 30- 30 CamScanner for pour planting. -a scanyed plak having

* t ml colony forming unit 2 no. of colonies & dilution factor volume of culture plate * formula for Colony forming unit / mL You have used 1 ml sample so your culture plat volume is 1 ml So CPU / ml = 290 x 10² = 290,ooo c fulme of original sample The result is 290,ooo bactena / 1 ml of CamScanner original mills

Comments Dilution 1 Suctor Number of celenico in plett No. of bacteria 1 me of milk T INTC INTC 290 290x lot Too many colonies Too many colonies countable plate countable plate Too two colories 4 The number of bacteria in 1 ml of - original milk quite obviously, should be same , because the sample as same. In serial dilution we are dilutine the original bacterial simple so that we get a countable plate to to find abfrow mete number of bacteria in the sample. So the dilution factor is for experimental accuracy of the number of bacteria in original sample will definitely be some bacteria d not Scanned with CamScanner who Counting back உay