Meet the Algae

My molecule hunting exploits are going to be based on two species of red algae - Plocamium angustum (to the right) and Plocamium microcladioides (to the left).  These are both types of seaweed found in New Zealand waters.  They contain chloroplasts as they produce food by photosynthesis.  The red colour is due to  pigments in the algae.

My first task is to extract a mixture of molecules from the algae.  This done by chopping a sample of the algae into small pieces, putting the pieces into a conical flask and then covering them with methanol.  The methanol acts as a solvent which molecules from the algae dissolve into.

I used 48.1 g of P. angustum and needed 300 mL of methanol to cover it.  The P. microcladioides was a larger sample.  It had a mass of 97.8 g and required 500 mL of methanol to cover it.

The conical flasks were then covered in aluminium foil and put into a dark cupboard.  Why? Some of the molecules being extracted could be light-sensitive - they might break down into something else if exposed to too much light.  The flasks were left overnight.

Almost immediately the methanol started turning green (not red!).  The green colour is probably due to chlorophyll from the chloroplasts in the algae.

You may notice that the flask has a code written on it. 'BPM1' refers to my 1st lab book - my initials are BPM. (If you look carefully you will see that I accidentally left the '1' off). '01A' means that it contains sample A (my P. angustum) and information about it can be found on page 01 of my lab book. Our lab books have pre-numbered pages and also produce a carbon copy of each page.  The lab books stay in the lab so anybody can check what is in a flask by going to the relevant lab book.  They also provide a permanent record of all practical work undertaken in the lab.