Question

7. If complement interferes with test results, the serum sample should be A. treated with an anticoagulant. B. frozen and thawed before testing C. heated to 56°C for 30 minutes. D. centrifuged at 3,000 g for 30 minutes. 8. Calculate the quantities of both diluent and solute needed to prepare 70 ml of a 10% solution of acetic acid. Show your calculations. 9. A new assay is used to test 120 samples from patients with a clinically confirmed diagnosis of the relevant infection and 50 samples from healthy control subjects. The test results were positive for 90 of the infected patients and positive for 10 of the healthy controls What is the sensitivity of the assay? A, 57% B. 75% C. 80% D. 90% Using the narrative of question 9, calculate the assay's specificity A. 57% B. 75% C. 80% D. 90% 10. How should a 1:50 dilution be made if the final volume needed is 10 mL? A. 0.1 mL of serum and 9.9 mL of diluent B. 0.2 mL of serum and 9.8 mL of diluent C. 0.2 mL of serum and 10.0 mL of diluent D. 0.5 mL of serum and 9.5 mL of diluent

Answer 1

7. If complement interferes with test results, the serum sample should be A. treated with an anticoagulant B. frozen and thawed before testing. heated to 56°C for 30 minutes. D. centrifuged at 3,000 g for 30 minutes If complement interferes with test results, the serum sample should be heatedt 56 degree centigrade for 30 minutes 10% acetic acid solution means, 10 mL of acetic acid in 100 mL solution (10 mL make up to 100 mL with diluent). The volume of solute is, C1V1 C2V2 (C1 Concentration of the pure form of acetic acid; V1 Volume of pure form of acetic acid required to make up 70% solution; C2 Concentration of final solution; V2 Final volume of the solution) (100%)(x) (10%) (70 mL) X 7 MI The volume of solvent is, 70 mL- 7 mL 63 mL