[DIYbio] science fair version of multicelluarity experiment

i'm looking for feedback on putting together a simplified version of the fascinating multicelluarity experiment described in a nytimes article here: 

http://www.nytimes.com/2012/01/17/science/yeast-reveals-how-fast-a-cell-can-form-a-body.html

the original paper and description of the experimental design are here: 

http://www.pnas.org/content/early/2012/01/10/1115323109.abstract

http://www.pnas.org/content/suppl/2012/01/11/1115323109.DCSupplemental

what i'd like to do is reproduce a simplified version of their "gravitational selection" experiment, which i've excerpted below (all the experiments are described in the supplemental material cited above) - the goal is make it suitable for a grade 5 school science fair project - i'm not a biologist so i'd appreciate any feedback people may have on the approach i'm thinking of - the idea here is to keep everything simple, inexpensive, and achievable at home, even if some of the scientific rigor is lost - my feeling is that if we see any change in yeast phenotype over the course of the experiment, then we'll have been able to demonstrate reaction to environmental selection - multicellularity would be a bonus

equipment will consist of:

o off-the-shelf brewer's yeast

o YPD broth for growing the yeast - 1 l for $35 from http://products.invitrogen.com/ivgn/product/A1374501

o flask agitator platform (constructed with lego mindstorms) to simulate "shaking at 250 x g" 

o dremelfuge to achieve "centrifuge at 100 x g for 10 s" - http://www.thingiverse.com/thing:1483 - i can borrow a dremel and fabricate the dremelfuge with a friend's 3D printer

o microscope - i don't have a microscope so this will be the big ticket item - i want to be able to take pictures of the yeast and it appears that 400X magnification should be adequate to view any changes in yeast phenotype (e.g. see http://www.youtube.com/watch?v=SoSgArEl-VE)  - i also want to be able to take pictures of what we see - the least expensive approach i've been able to find is the $160 celestron 44340 http://www.celestron.com/science_education/microscopes/lcd-digital-microscope.html - any cheaper alternatives to this?

i don't know how to best maintain a 30 °C environment though - i was thinking putting everything in a cardboard box with a lightbulb and a cheap digital indoor/outdoor thermometer with a probe ($12 from the hardware store) - my understanding is that, as long as the temp stays near 30 °C and lower than 37 °C, the yeast should be happy

here are a few questions/observations i have about the experiment itself:

o we won't be able to guarantee initial genetic uniformity of the yeast since we'll be starting with off-the-shelf brewer's yeast - hopefully this is ok

o i don't know how much of the brewer's yeast to start with

o to view the yeast with the microscope, my understanding is that i'll need concave slides

o i'm not sure what the easiest approach to achieving sterility should be - will boiling the glass tubes be sufficient?

i'd appreciate any feedback on this - i intend to keep the list apprised of our progress/results

thanks!

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From http://www.pnas.org/content/suppl/2012/01/11/1115323109.DCSupplemental/pnas.201115323SI.pdf

Gravitational Selection, Experiment 1. Ten replicate populations of initially genetically uniform dioloid Saccharomyces cerevisiae strain Y55 were grown in 10-mL aliquots of Yeast Peptone Dextrose (YPD; per liter: 10 g yeast extract, 20 g peptone, 20 g dextrose, pH 5.8) in 25- × 150-mm glass culture tubes at 30 °C, shaking at 250 × g. Every 24 h, the entire population was transferred to a 16- × 150- mm sterile glass tube and allowed to settle on the bench for 45 min, and the bottom 100 μL was transferred to the next 25-mm culture tube containing fresh rich media. After 7 d, the transfer step was made more efficient: 1.5 mL of each culture was removed and centrifuged at 100 × g for 10 s, and then the bottom 100 μL was transferred to the next 25-mm culture tube containing fresh media.