EarlyAmateurZymurgist
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- Aug 4, 2013
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A fellow forum member asked me to demonstrate how to plate yeast from a bottle. While I do not have a complete photo shoot, I was able to shoot a couple of photos of a yeast strain that I am currently plating.
I streaked the plate shown below earlier this week. I was in a hurry and it was the first time that I have attempted to perform a four-quadrant streak in such a small petri dish (the dish is only 60mm wide x 15mm tall). Being a cheap soda lime petri dish, it doesn't have a reference point mark on the bottom like a high-quality borosilicate petri dish. Because the petri dish is so small, I thought that I could get away with rotating the plate by pressing down on the top of the dish and turning. As can be seen in the photograph shown below, I did manage to accomplish a two-quadrant streak using the push down and turn technique.
The candidate colonies are enclosed in the rectangle in the photograph shown above. These colonies demonstrate good morphology. They are also far enough apart to harvest individually. Each colony is the offspring of a single yeast cell; therefore, the colonies are single-cell isolates (a.k.a. pure cultures). The smaller colonies on the plate are more than likely respiratory-deficient mutants (a.k.a. petite mutants). This plate was streaked with yeast that was revived from a bottle of bottle-conditioned beer; therefore, petite mutants are par for the course.
The photograph shown below includes a new plate that I streaked this evening because I was unhappy with the first plate. One can see the distortion in the middle of the medium where I cooled my loop between quadrants.
If one looks at about the two o'clock position on the edge of the petri dish shown below, one will see a little black spot. That black spot is a reference point marker that I put on the bottom outside edge of the dish with a Sharpie. I used that marker to rotate the plate ninety degrees between streaks.
Hopefully, I will be able to find the time to shoot the plate that I streaked this evening after it has been incubated. I should get well-separated colonies in the fourth quadrant of the new plate.
I streaked the plate shown below earlier this week. I was in a hurry and it was the first time that I have attempted to perform a four-quadrant streak in such a small petri dish (the dish is only 60mm wide x 15mm tall). Being a cheap soda lime petri dish, it doesn't have a reference point mark on the bottom like a high-quality borosilicate petri dish. Because the petri dish is so small, I thought that I could get away with rotating the plate by pressing down on the top of the dish and turning. As can be seen in the photograph shown below, I did manage to accomplish a two-quadrant streak using the push down and turn technique.
The candidate colonies are enclosed in the rectangle in the photograph shown above. These colonies demonstrate good morphology. They are also far enough apart to harvest individually. Each colony is the offspring of a single yeast cell; therefore, the colonies are single-cell isolates (a.k.a. pure cultures). The smaller colonies on the plate are more than likely respiratory-deficient mutants (a.k.a. petite mutants). This plate was streaked with yeast that was revived from a bottle of bottle-conditioned beer; therefore, petite mutants are par for the course.
The photograph shown below includes a new plate that I streaked this evening because I was unhappy with the first plate. One can see the distortion in the middle of the medium where I cooled my loop between quadrants.
If one looks at about the two o'clock position on the edge of the petri dish shown below, one will see a little black spot. That black spot is a reference point marker that I put on the bottom outside edge of the dish with a Sharpie. I used that marker to rotate the plate ninety degrees between streaks.
Hopefully, I will be able to find the time to shoot the plate that I streaked this evening after it has been incubated. I should get well-separated colonies in the fourth quadrant of the new plate.
