Cheap (household) alternative to proto-slow??

[Charles J. O'Kelly]

|> In article <146880 at hydra.gatech.EDU>, gt2617c at prism.gatech.EDU (Brad
|> Smalling) wrote:
|> 
|> > From my high school biology classes, I remember using a viscous fluid called
|> > proto-slow (or something similar) to slow down hyper protozoa.  Is there
|> > a generally accepted alternative?  My guess is that it must be water soluble,
|> > thicker than water, have a neutral pH, and be non-lethal to our single celled
|> > friends.  Any ideas?  (I just have this _feeling_ that ProtoSlow is a trade-
|> > mark and costs big bucks for teeny-weeny little bottles.)
|> > 
|> > Thanks,
|> > --
|> > 
|> >  Brad Smalling : Sr.EE : Georgia Tech : Atlanta, GA : gt2617c at prism.gatech.edu
|> >  = I never said that.  You misunderstood me. ======== ccastbr at prism.gatech.edu

I don't think Proto-Slow is that expensive (you might look it up in the Carolina Biological
Supply Co. catalogue - not handy to me at the mo).  However, neither it nor any of the other
"classical" tricks has ever made me very happy.

Try this.  Get ahold of some agar, either bacteriological grade stuff from the lab or cooking
grade from the oriental food counter.  Plain agar, no bacterial food or nasty fluorescent Kool-
Aid colors :-).  Agarose is even better if you can get it.

Boil up about a 1% solution, and dispense a drop on a
slide.  While it's cooling, make a shallow well in the center with a Pasteur pipette or similar
instrument.  When the agar has gelled, add a drop of your cells and a coverslip.

Protozoa in the well will swim normally.  Those outside the well might be crushed.  Those 
between will be nicely pinned.

The method takes some trial and error (agar concentration, amount of water, depth of well), but
when it works, which is lots more often than any other method, it's gorgeous.  Pro protist
photographers can't be wrong ...

good luck!

Charley O'Kelly
Mad Protistologist
okellyc at bch.umontreal.ca