A specimen of urine contains 30 bacterial cells per microliter. How many cells are present in a milliliter?

To find the number of bacterial cells in a milliliter of urine, we need to convert the volume from microliters to milliliters and multiply it by the concentration of bacterial cells.

Given:
Concentration of bacterial cells in urine = 30 cells per microliter

Step 1: Convert microliters to milliliters.
1 milliliter (mL) is equal to 1000 microliters (μL). Therefore, we can use the conversion factor:
1 mL = 1000 μL

Step 2: Calculate the number of cells in a milliliter.
Multiply the concentration (given as cells per microliter) by the volume (converted to milliliters) to get the number of cells in a milliliter.

Number of cells in a milliliter = Concentration × Volume
Number of cells in a milliliter = 30 cells/μL × 1 mL/1000 μL