Tree Cells

So my trusty assistant Nicole and I have been trying to separate cells from a wood core of a Red Oak so that we can put them though our new flow cytometer. So far this is our procedure -

• We chop the core up into little bits.
• We boil them in a mixture of hydrogen peroxide and glacial acetic acid under liebig condenser for three hours.
• We cool the mixture and vacuum filter through an 8 micron filter rinsing a couple of times with saline to clear out all the acid.
• We take the filter paper and use a needle to tease apart any remaining lumps.
• Scrape the filtrand and rinse the paper into a small amount of saline solution with pectinase and EDTA.
• Stir the suspension on a hot plate at about 40 degrees for 3 hours, subjecting it to ultrasound for 3 minutes at the beginning middle and end.
• Draw the suspension into a syringe and force through a 400 micron polyethylene mesh.

The resulting filtrate is found to contain mostly free cells. These are rectangular and roughly 15 microns across with lengths ranging from about 50 to 100 microns. They have a clearly visible cell wall about 2 microns thick with what appear to be small 1 micron wide pores randomly distributed around them. Here are some microscope pictures we took of the samples.

Without the final mesh filter step we find that there are also an abundance of other larger structures. This includes long smooth fibres (which appear to be hollow) 15-20 microns wide and 1-2 mm long. There are also sheets and tubes of another material which seem to be covered in small pores.

Without the pectinase step we find many more of the rectangular cells stuck together in regular stacks.

Whale

So this is my latest blender creation - yes a whale, for no reason in particular!

Too much time

So, one of my little projects at the moment is trying to learn how to use Blender (the open source 3D modeling/animation package). I've been using it this term for my lectures. This is my latest creation, for my quantum 2 lectures, the first few squared spherical harmonics. I wrote a python script to draw the curves. Of course I could have downloaded an image of these and so not stayed up until 1am writing my script and so have already had my actual lecture prepared ... but where's the fun in that!