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Editor,
By the way, the TCS site continues
to look great! Good stuff and well done.
I am now in process of becoming a first
time, 71-year old beekeeper. I just hived the queen and bees
last Saturday. If all goes well, this may also provide some
interesting article possibilities about bees, honey and flowers.
Richard Haynes
Shawn,
How are things going? I guess since I have
"a McArthur Fellow in my pocket," I can start using
one, can't I?
I wanted to ask you about biological stains,
particularly Trypan Blue or Chlorazol Black that are used
to stain plant cells. I am interested in these two stains,
because I am interested in looking at the mychorriza on plant
roots under a microscope. Mychorrhiza are fungi that colonize
plant roots and form a symbiotic relationship giving the plant
extra phosphorus from the soil while the plant gives them
extra carbon compounds from photosynthesis. To see these structures
I must, 1) cleanse the roots in NaOH and 2) soak the roots
in a mixture of the stain + H2O + glyerol + lactic acid.
How can I buy biological stains? Can I make
them at home (even more fun)?
Reggie Smith
Reggie,
I was just thinking about you this morning!
Thanks for writing.
Many of the commercial dyes for biology come
from the natural world, so yes, you can make them. All of
the ones that I have used are water soluble. Just about any
natural substance that stains your hands can be used to stain
tissues on a microscope slide. Red beats contain a dye that
is used in food coloring and that stains cell walls. Saffron,
a spice that comes from the dried stigmas of the saffron crocus
plant, yields a potent yellow dye. (You can purchase saffron
at most well stocked supermarkets.) There are many other examples
lurking on the shelves of your neighborhood market.
It is very simple to extract and concentrate
the dye. Just mechanically mash the material up into a pulp
to break open the cell walls and then leach out the pigment
with hot water or alcohol (depending on whether you or not
you intend use the concoction as part of a fixing agent).
Then let most of the liquid evaporate under gentle heat. (One
must be careful if using the sun as a heating source, since
the UV in sunlight destroys most natural pigments.) A garlic
press is a great tool for breaking up cell walls!
Off hand, I don't know how to make Trypan
Blue or Chlorazol Black. But I'm sure the process is described
in the literature somewhere. (Maybe using a google
search.) The folks a BioQuip (www.bioquip.com) manufacture
some of the stains they sell, so they may be willing to tell
you. If not, they'd be willing to sell you anything they have
in stock. I know that Trypan Blue is listed as a "known
carcinogen" so there may be some restrictions regarding
its use. But other stains that you make yourself may work
as well. I have some black walnut trees and have often wondered
whether the black pigment on the inside of their nut shells
could be used as a biological dye. Perhaps this season I'll
find out!
I hope you'll write up your experiences in
securing these dyes and publish them in The Citizen Scientist.
Lots of our members would benefit from what your work here,
I'm sure.
Hope this helps. Let me know if there is anything else I
can do to help you.
Shawn Carlson, Ph.D. 
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