Week 02 - Yeast mating

Submitted by kdorfman on Thu, 07/20/2023 - 18:16

Yeast labs, week of 9/11/23 (2nd week of classes, 1st complete week)

See notes here

Total YED plates for the week for 4 sections plus prep: 75

Students mate 3 A mating types with 3 alpha mating types

Take YED plates out early so they stop sweating.

Make an assembly line of 7 stations (use templates):

station activity materials
1 label plate YED plates, labeling template, Fisher Finest marker
2 plate HA1 across 3 small plates of HA1 on YEPAD, sterile toothpicks, used toothpick bucket
3 plate HA2 across 3 small plates of HA2 on YEPAD, sterile toothpicks, used toothpick bucket
4 plate HAR across 3 small plates of HAR on YEPAD, sterile toothpicks, used toothpick bucket
5 Plate HB1 down, mixing carefully with the A strain already there, new toothpick each time 3 small plates of HB1 on YEPAD, sterile toothpicks, used toothpick bucket
6 Plate HB2 down 3 small plates of HB2 on YEPAD, sterile toothpicks, used toothpick bucket
7 Plate HBR down 3 small plates of HBR on YEPAD, sterile toothpicks, used toothpick bucket

For mating, students need these strains on YEPAD plates so they all start out white:

  • HA1
  • HB1
  • HA2
  • HB2
  • HAR
  • HBR

For observation, students need these strains on YED plates so their colors can be observed:

  • HA0
  • HB0
  • HA1
  • HB1
  • HA2
  • HB2
  • HAR
  • HBR

For observation of colors, make demo plates (maybe 4 of each):

  • 4 YED plate with 4 A strains
  • 4 YED plate with 4 alpha (B) strains

(If you let the parental strains sit on YED more than a couple of days, the mutant strains turn red, and the red color will still be there even after there are heterozygous diploids with complementation.)

List of yeast strains

A types alpha (B) types
HA0 (WT) HB0 (WT)
HA1 (ade1) HB1 (ade1)
HA2 (ade2) HB2 (ade2)

Start 6 strains at least the Friday before the first lab.

Instructors should make some mating plates to have in the fridge to hand out when student plates are bad.

Yeast Mating Templates