Measuring yeast growth by spotting serial dilutions

Measuring growth of yeast by spotting serial dilutions of liquid cultures
Set up 4 microfuge tubes per culture each containing 900 ul sterile water.
Add 100 ul of yeast culture* to tube 1, close top and vortex to mix.
Remove 100 ul of diluted culture from tube 1 and add to tube 2; mix.
Continue serial dilutions out to tube 4.
Spot 10 ul of each dilution in a row onto agar plates; allow to dry and incubate 30 C for 1-3 days
This plate shows growth of serial dilutions of 6 different yeast cultures (only 3 dilutions for each in this
case). One could calculate the cell concentration using these results by counting the colonies in the lowest
dilution and then multiply by the dilution factor.
*When testing yeast two-hybrid strains containing both the bait and prey plasmids, grow strain in SCD-leutrp media to saturation. Spot diluted cultures onto both SCD-leu-trp and SCD-leu-trp-his-ade. The latter
plates will test for bait/prey interactions.