Anonymous
Anonymous asked in Science & MathematicsBiology · 2 months ago

why is my teacher asking me take out 10ul of solution from my solution bottle for serial dilutions and not from my sample?

So my experiment was that I will have e.coli bacteria in a spray bottle to spray onto a tile surface and too see how many bacteria were transferred. I then swabbed it onto a plate. My teacher told me as the plate had too many colonies id need to dilute it . So she said that I will go into the original spray bottle and scoop out 10ul using an inoculating loop. I am confused why. Am I not suppose to take out a scoop from my plate as thats what I want to dilute? is she assuming that when I sprayed my solution from the bottle, around 10ul was sprayed out onto the tile surface hence taking out 10ul from my solution bottle??

1 Answer

Relevance
  • 2 months ago

    Your sample concentration is to high. Your bottle solution is less concentrated. I assume the solution bottle concentration is known and it would have less colonies. 10ul to another bottle with solvent,would make it less concentrated with less colonies. 

Still have questions? Get your answers by asking now.