Given a serum-based cholesterol standard of 200.0 mg/dL, what is the concentration of cholesterol in a patient's sample with absorbance results?

The concentration of cholesterol in a patient's sample is determined through a calibration curve, which relates absorbance readings to cholesterol concentration. For this question, the standard has a known concentration of 200.0 mg/dL, and the patient's sample is being compared against this standard based on its absorbance values.

When absorbance results from the patient's sample are measured, they correspond to the concentration of cholesterol within that sample. The process typically involves utilizing the standard's known concentration to establish a linear relationship: as the concentration of cholesterol increases, the absorbance also increases proportionally due to Beer's law.

If the absorbance of the patient's sample yields a value that correlates with a concentration of 172 mg/dL based on the calibration curve, it indicates that this concentration is lower than the standard but meaningful in a clinical context. This concentration would typically suggest that the patient's cholesterol level, while still relevant for medical analysis, is less than the 200 mg/dL standard.

Therefore, if the calculated concentration based on the calibration curve aligns with the 172 mg/dL reading for the patient's sample, it accurately reflects the amount of cholesterol present in that sample, making it the correct answer.