Measuring Algal Growth Rate

[deleted-478088]

Hello,

I am currently conducting a science fair project that tests the effects of initial salt concentration (in the growth medium) on the growth rate and lipid production of the algae species Nannocloropsis occulata. In order to measure growth rate, I was planning on simply using a hemocytometer to perform a direct cell count.

However, under certain conditions, the algae cells, which are normally floating individually, seem to clump together. This can be seen in the images below (taken under a microscope at 100X and 400X magnification).
https://ibb.co/eH36Wk
https://ibb.co/cugFP5

So, my question is: Is there any way to artificially separate clumped algae cells so that they can be counted under a microscope?

I have read a study (linked here: https://link.springer.com/chapter/10.10 ... -5479-9_16) that talked about using a Potter Homogenizer. However, I do not know what this is, or how to use it.

Any help would be appreciated, thank you!

[deleted-357169]

Hello there,

Here is what a potter homogenizer looks like: https://www.thomassci.com/Equipment/Gri ... g%20Potter

They are expensive but if you have access to a research lab, they most likely will have one.

I believe you should be able to achieve similar results using a plastic pestle (https://www.carolina.com/catalog/detail ... gJEDfD_BwE) in a 1.5mL eppendorf tube.
(https://www.fishersci.com/shop/products ... /p-4669177). I used to use these to break up plant tissue. You could put 500ul or so into the tube and then use the plastic pestle to try and break up the clumps a bit. I hope this helps! Good luck!

[deleted-478088]

Hello there,

Here is what a potter homogenizer looks like: https://www.thomassci.com/Equipment/Gri ... g%20Potter

They are expensive but if you have access to a research lab, they most likely will have one.

I believe you should be able to achieve similar results using a plastic pestle (https://www.carolina.com/catalog/detail ... gJEDfD_BwE) in a 1.5mL eppendorf tube.
(https://www.fishersci.com/shop/products ... /p-4669177). I used to use these to break up plant tissue. You could put 500ul or so into the tube and then use the plastic pestle to try and break up the clumps a bit. I hope this helps! Good luck!

Thank you very much AJ, that definitely helps! As soon as I can get access to that equipment, I will make sure to give that a try!

Just a quick question: Is there a difference between the Eppendorf Tube and a Microcentrifuge Tube?