Fibrinogen is a protein that is produced by the liver and found in human plasma.

Question

Fibrinogen is a protein that is produced by the liver and found in human plasma. Its concentration in plasma is clinically important. Many of the analytical methods used to determine the concentration of fibrinogen in plasma are based on light scattering following its precipitation. For example, da Silva and colleagues describe a method in which fibrinogen precipitates in the presence of ammonium sulfate in a guanidine hydrochloride buffer. Light scattering is measured nephelometrically at a wavelength of 340 nm. Analysis of a set of external calibration standards gives the following calibration equation: Is = 4.66+ 9907.63*C where Is is the intensity of scattered light and C is the concentration of fibrinogen in g/L. A 9.00-mL sample of plasma was collected from a patient and mixed with 1.00 mL of an anticoagulating agent. A 1.00- mL aliquot of this solution was then diluted to 250 mL in a volumetric flask. Analysis of the resulting solution gave a scattering intensity of 44.70. What is the concentration of fibrinogen, in gram per liter, in the plasma sample?

Explanation / Answer

scattering intensity of plasma sample = 44.70

Using,

Is = -4.66 + 9907.63C

C = (44.70 + 4.66)/9907.63 = 4.982 x 10^-3 M in 250 ml solution

Concentration of Fibrinogen in 1 ml sample = 4.982 x 10^-3 x 250/1 = 1.245 M

concentration of fibrinogen in original 9 ml sample = 1.245 x 9 = 11.205 M = 11.205 x 340000 = 3.81 x 10^6 g/L  

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.