Thursday, 23 July 2015

Working with algae

Algae culture room / magic bubbly colour bottles

Laminar flow cabinet
I've been learning a lot of things while I'm working at the Fisheries Institute here. Today I got to practise using a haemocytometer  to work out the algal concentration of a solution - very important to get this right for the experiments that we are about to begin here!

To retrieve the algae from the stock cultures, we work in the laminar flow cabinet - this is similar to a fume hood (which protects the person working with it by drawing air in from the front so that any nasty chemicals inside the hood don't get drawn out into the air where the person is working), but it works the opposite way round (so instead of protecting the user from what is inside the cabinet, it protects what's inside by drawing air in through the top and out through the front - so nothing from the users side can enter the cabinet and contaminate whatever is being worked on).

Haemocytometer grid
(as the name suggests these
can also be used to count blood
If the algae that you want to count is motile then a small amount of formalin solution has to be added to kill them (or counting them would be a complete nightmare). Formalin is a solution of formaldehyde in water, and it's pretty nasty stuff - stronger solutions of the stuff are used for the embalming of human remains! The algal culture must be shaken to suspend any cells that have settled on the bottom - and then a small amount is pipetted onto a haemocytometer (this is a microscope slide with a teeny tiny grid of very exact measurements etched into it) with a cover slide placed on top of it.

Then comes the counting! You can count the amount of cells in different sized boxes - dependent on just how many cells are in the solution (so if there are thousands you might want to count in a very small box and just scale up the count at the end).

And then some maths to work out the overall concentration in CELLS/ML.

Now with harmless algae - for example some of the algae they use at the Fisheries Institute to feed the oysters - any waste algae can just be thrown down the sink....


The terrible algae in question - Alexandrium

This algae can cause PSP (paralytic shellfish poisoning) - which can concentrate in shellfish and, when eaten, can cause illness in humans. PSP can affect the nervous system and cause paralysis - severe PSP can even cause severe illness and death!

Example of an Alexandrium sp. bloom
Because the Fisheries Institute does a lot of work on shellfish we have to be exceedingly careful with the Alexandrium culture so as to ensure that we don't contaminate any of the feed algae or any of the water that could get into the shellfish. We also have to be careful not to put any Alexandrium down the drain in case it makes it's way into the bay at all - the Fisheries Institute (and especially me) don't really want to be responsible for mass ruining of thousands of oysters in the Bay! So all excess Alexandrium is carefully soaked up into tissue and binned - and the equipment we use will be double washed in alcohol solution. We will be SUPER CAREFUL.

When we counted the Alexandrium yesterday it was 70,000 cells/ml, and today it was 110,000 cells/ml! It's growing fast! And it's nearly ready for the experiment!!


  1. Dun dun DUNNNNNNN hahaha that made me laugh! Good to read things are going well!!xx

  2. It took me far to long to realize you'd pain-shopped the devil horns onto the Alexandrium sp. Was getting really quite excited about how monstrous this algae looked under microscope. Those two years of Microbes clearly did nothing for me...

    1. Caz you are a SCIENTIST.. (also "pain-shopped")