TOO MANY CELLS IN YOUR TEST TUBE?

Time to perform a virtual dilution!

Imagine that you have 125,000,000,000 (1.25 x 10¹¹) bacterial cells in 10 milliliters of water—far more than you need to conduct your lab experiments. Click a button below to select the method that will result in the least number of cells in the last dilution tube.

dilution animation

Option 1

Dilution

Here's What we did:

View Graph

Nice choice! Let’s see dilution in action.

You selected the ¼ x ¼ x ¼ x ¼ series to reduce the total number of cells.

In each of the four steps, one-fourth of the cells in the test tube were moved to the next test tube. This step-wise movement results in a consistent drop in the number of cells.

We can plot the concentration of cells in each of the four test tubes as a linear relationship on a graph.

Try the math first on your own, then click the boxes to the left to see the effect of the dilution series (and the math).

OPTION 1: Dilute the cells by: 1/4 x 1/4 x 1/4 x 1/4

(At each step, one-fourth of the cells are moved to a new test tube of water, and we divide the number of cells by four.)

OPTION 2: Dilute the cells by: 1/10 x 1/10 x 1/10 x 1/10

(At each step, one-tenth of the cells are moved to a new test tube of water, and we divide the number of cells by 10.)

OPTION 3: Dilute the cells by: 1/100 x 1/100 x 1/100 x 1/100

(At each step, one one-hundredth of the cells are moved to a new test tube of water, and we divide the number of cells by 100.)

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