You are a microbiology lab technician and you need to quantifythe viable cell concentration in your stock culture beforebeginning an experiment. Since you do not know the range, youperform a serial dilution over several orders of magnitude. You usethe pour plate method and plate 1 ml for each dilution level, induplicate. Give the most accurate value for the number of viablecells in the original stock culture, in CFU / ml. Just enter anumber, do not type the units!
Since you want the practice, you attempt a count for all plates,even though some are likely too numerous to count. Only use valuesthat give you the best accuracy. That means only use values thatare a \"countable number\" of colonies (see text section).
Dilution series colony counts:
1:10: 860, 745
1:100: 123, 114
1:1000: 11, 15
1:10,000: 2, 4
