How do you check the heart rate of daphnia under a microscope?

The links below show the experimental methods used by researchers testing the heart rate of daphnia under a microscope. This is what they say....

To measure the responding variable a microscope and video camera were used to record how many beats of the daphnia heart rate occurred in 10 seconds. These pulses were recorded with a video microscope and slowed down to accurately count the beats.

The second website says that you can use a dissecting microscope, placing the individual Daphnia in a small drop of water so that it cannot swim out of your field of view. You can also use a compound microscope with a low-power objective. In this case, you will need a special microscope slide called a depression slide. The depression slide has a polished, concave depression at the center that can hold a large drop of water. An individual Daphnia is placed in the depression and then coverslipped for viewing. In both cases, you want to make your measurements quickly, so that the Daphnia does not become stressed in the small volume of water.

How do you check the heart rate of daphnia under a microscope?

If you have problems with the microscopy illumination (=cannot detect the heart), try following:

- change from bright field to phase contrast

- if you do not have phase contrast illumination, try to increase the contrast of your image by either closing the condensor diaphragm or by lowering the position of the condensor

Good luck!

How do you check the heart rate of daphnia under a microscope?

I%26#039;ve done it before myself.

Lassoo the daphnia in cotton wool and look at it under a microscope. You can see its little heart beating away. Keep him nice and moist and try not to upset him too much. Just use a stopwatch and count the number of beats in one minute (or less if you are lazy).