I am currently using a track dilution plating method for my mycobacterial experiments due to large number of samples and their dilutions. I start taking the counts as the colonies start appearing till the day they start crowding on the track. Does anyone know the validated range of colonies to be counted for each track? According to my knowledge, for each dilution , more than 300 colonies should not be counted.
Details : plating volume is 10 uL
Dilution : N/25
Day of colony appearance : 8- 12 ( varies with strain)
usually for pour plate methods counts should be done from 10 to 300 cfu, and for spread plating from 10 to 150 cfu..using two plates by dilution. If you are using the spiral plating method you can count from 10 to 3000
Nevertheless you can do other approach if you not are interested in a very exact count, the droop dilution method.
best regards
- Badges
- Science topic