Table of Contents

• 1: Recap the story
• 2: Count them all?
• 3: Direct count
• 4: Light scatter (spectrophotometer)
• 5: The dilemma of the dead cell
• 6: Viable plate count
• 7: Comparison of methods
• 8: Summary

Count them all?

Let's get one thing clear at the outset. Given that the infective dose for cholera is about 1 million bacteria, we are expecting to find very high numbers. Do we want to count every single one? Do we need to?

So, having established that we can't count them all, what else can we do?