|MadSci Network: Microbiology|
Tayuba, I suggest using a dissecting scope of sufficient magnification that you can clearly see the heart beating. A compound scope using a relatively low magnification objective lens will also work. I suggest using a mixture of protoslo and water to keep the Daphnia immobile while you perform the experiment. The trick is to slow the Daphnia down enough that the heart rate can be determined without unduly stressing the little beast. Also, use a depression slide and a cover slip. Turn off the light source when you are not actually observing in order to keep from heating up the slide and to keep evaporation to a minimum. I hope these tips help you out!
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