Reliable liquid worm counting

Model Organism: Worms Methods & Reagents
1

Hi folks,

I’m trying to find a reliable and accurate way to count worms in liquid cultures. What I typically do is shake the worms in solution and take three 5 uL aliquots of worms and count them under a dissecting scope on a cover slip. I find pretty high variability among the aliquots, sometimes greater than 50% variability. In some future studies I have planned I require greater confidence in my worm counts. I don’t have access to a COPAS instrument. Does anyone have any advice or suggestions for better worm counting techniques?

Thanks for your help!

2

I usally count worms from liquid culture in two (or three) dilutions (e.g. 1:2 and 1:4, or 1:10) also I add some Tween to the dilutions (approx. 0.01% final) to reduce sticking of worms to tips while pipetting. I then count worms in a 10µL droplet.
good luck.

3

Thank you Marlon! I will try that and see if it improves the precision of my counting.