Wednesday, 2 October 2013

Chocolate Truffle White Blood Cells DIY

Sprout is really interested in human and animal bodies at the moment, and, this past couple of weeks, blood in particular. He found out about blood cells a while ago, and is now interested in the different sorts of white blood cells and what they look like and do. He learns primarily kinaesthetically and visually, and search as I might I couldn't find the detail he wanted in an appropriate form or activity idea for his age or level of understanding. So I decided on blood cell chocolate truffles :)

What you'll need:
Large bar of dark chocolate
Tub of soft cheese
Large bar of whatever chocolate you want to coat them in
Sprinkles - red, blue, pink
Chocolate vermicelli
Other vermicelli 
Writing icing in various colours

First, we made chocolate truffles by melting one large bar of dark chocolate (cheapy supermarket stuff was fine), and stirring in a tub of soft cheese (Asda smart price). We rolled it into five slightly different sizes of balls. I then tried to melt some white chocolate to coat them in, but went wrong somewhere along the way, and tried again with milk chocolate which worked much better, and the colour didn't really matter (the cells aren't really white after all!)
As we rolled the truffles in the melted chocolate, we rolled the smallest ones (basophils) in blue sprinkles, the next ones up (neutrophils) in pink sprinkles (or in this case yellow and pink, enthusiastic as I am I wasn't going to spend half an hour picking the yellow ones out!), and some of the middling ones (eosinophils) in red sprinkles (which I didn't have so I popped some on with red writing icing). We left some of the middle sized ones (lymphocytes) and the largest ones (monocytes) with no sprinkles, and I briefly explained the difference between granulocytes and agranulocytes. 
We then added nuclei using white writing icing: lobed for the basophils, more lobes for the neutrophils, lobes again for the eosinophils, round-ish ones on most of the lymphocytes, a long one on some of the lymphocytes to be young band lymphocytes (and talked about band granulocytes and what their appearance means), and on the monocytes the characteristic large kidney-shaped nucleus. 



Then we played! We used two different colours of writing icing to be heparin and histamine coming out of the basophil, and talked about how they acted to bring helpful stuff to the area. 
We used chocolate vermicelli to be bacteria entering a wound, and the neutrophil bacterial slayer (he thought that was a very cool term!) phagocytised them. 
A parasitic worm (piece of cooked spaghetti) invaded, and, using a different colour writing icing as the eosinophil's toxin, it was conquered. 
We divided the lymphocytes into B, T and Natural Killer cells (which he thought was even better than bacterial slayer!). The T cells went round helping the other cells, the B cells produced (light vermicelli) antibodies to bind with more (chocolate vermicelli) bacterial invaders. We used black writing icing to be the Natural Killer cells' defence when it recognises non-self. 
The monocyte dramatically squished.. erm, phagocytised, the neutrophil once it had died.


We had loads of truffles left over, so Sprout and Squidge both designed some cells. Squidge's were all muscle cells from various parts of the body, and he told me what they moved (his favourite were the toe muscles)...



...while Sprout's were hair follicle cells, brain cells, blood cells, muscle cells and heart cells. He drew a classification tale underneath of various body parts, and then explained to me which cells would be found in which parts of the body, it was brilliant! He then surrounded the blood cells with plasma (yellow writing icing). 



We've got another blood activity planned for later on, but for now I'm off to have a coffee and a couple of neutrophils :)



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