# Question #2766f

##### 1 Answer

Jan 30, 2015

There are 5.25 × 10⁷ cells/mL in the original sample.

**Step 1.** Find the volume of a box.

I assume that the depth of the box is 0.1 mm. Then

Note: 1 mL = 1 cm³ = 1000 mm³.

**Step 2.** Calculate the concentration of cells in a box.

**Step 3.** Correct for the dilution factor (DF).

Your original sample was 30 times more concentrated (DF = 30).

Original concentration = DF × concentration in slide box = 30 × 1.75 × 10⁶ cells/mL = 5.25 × 10⁷ cells/mL

The original sample contained 5.25 × 10⁷ cells/mL.