After making a 1:200 dilution and counting 336 red cells in 0.2 mm², what is the RBC count?

After making a 1:200 dilution and counting 336 red cells in 0.2 mm², what is the RBC count?

• A. 1.68 × 10^12/L
• B. 3.36 × 10^12/L
• C. 4.47 × 10^12/L
• D. 6.66 × 10^12/L

Answer: (B)

To determine the RBC count, it is essential to understand how to apply the results from the dilution and the cell count to obtain the final concentration of red blood cells in the sample. Starting with the dilution factor of 1:200, this means that the original sample has been diluted by a factor of 200. The count of 336 red cells observed in a volume of 0.2 mm² must then be converted into a representative count per liter in order to reflect the actual RBC concentration in the undiluted sample. First, calculate the number of cells per mm² in the diluted sample: RBC per mm² = 336 cells / 0.2 mm² = 1680 cells/mm². Next, since the dilution factor is 200, the actual count in the original undiluted sample can be found by multiplying this diluted count by the dilution factor: RBC per mm² in the original sample = 1680 cells/mm² × 200 = 336,000 cells/mm². To convert this value to a count per liter, remember that 1 mm² is equivalent to 1,000,000 μm². Therefore, to find the count in an entire liter (which is 1

To determine the RBC count, it is essential to understand how to apply the results from the dilution and the cell count to obtain the final concentration of red blood cells in the sample.

Starting with the dilution factor of 1:200, this means that the original sample has been diluted by a factor of 200. The count of 336 red cells observed in a volume of 0.2 mm² must then be converted into a representative count per liter in order to reflect the actual RBC concentration in the undiluted sample.

First, calculate the number of cells per mm² in the diluted sample:

RBC per mm² = 336 cells / 0.2 mm² = 1680 cells/mm².

Next, since the dilution factor is 200, the actual count in the original undiluted sample can be found by multiplying this diluted count by the dilution factor:

RBC per mm² in the original sample = 1680 cells/mm² × 200 = 336,000 cells/mm².

To convert this value to a count per liter, remember that 1 mm² is equivalent to 1,000,000 μm². Therefore, to find the count in an entire liter (which is 1