chempath tut1

1. Multiple choice: choose the correct answer; showing how you obtained
your answer.

1.1 What is the molarity of a solution that contains 18.7g of KCl in
500 ml?
A. 0.1
B. 0.5
C. 1.0
D. 5.0

1.2 How much 95% alcohol is required to prepare 5 L 70% alcohol?
A. 2.4 L
B 3.5 L
C. 3.7 L
D. 4.4 L

1.3. How many milliliters of concentrated H2SO4 are required to prepare 10L of 0.1 N H2SO4?
A. 1.84
B. 9.20
C. 27.5
D. 54.4

1.4 How many grams of Na0H are required to prepare 2500 mL of a 4 M solution?]
A. 40
B. 100
C. 160
D. 400
1.5 What is the relative centrifugal force of a centrifuge operating at 1500 rpm with a radius of 10 cm?
A. 625
B. 699
C. 252
D. 6988

1.6 Which of the following weighs the most?
A. 0.1 ng
B. 0.01 g
C. 1.0 mg
D. 1000 pg

1.7 What amount of NaCl is needed to obtain 50 mg Cl?
A. 19.6 mg
B. 30.3 mg
C. 50.0 mg
D. 82.4 mg [7 x 3 = 21]



2.1 Explain the term occult blood, with details of the type of specimen
required for analysis. [3]
2.2 Give 3 cases where one can get a positive result. [3]
2.3 Explain how one can obtain a false positive result. [1]
2.4 Name a type of occult blood test that may be obtained from suppliers / manufacturers. [1]



3. Discuss the assessment of foetal maturity and reasons why amniotic fluid is a choice of specimen for analysis. [5]



4. Differentiate between antigen and antibody detection using the sandwich technique. [6]
5. Dr Peter N is a Pathologist who has completed the qualification as an endocrinologist. He wishes to leave the state hospital and open up a RIA laboratory. Name all the requirements that are necessary for this venture. [8]

6. Draw a fully labelled diagram to illustrate a competitive binding assay. [5]

7. With the aid of separate diagrams show how standard curves are generated in a radioimmunoassay and also how patients’ results are obtained from the graph. [12]

8. Explain counting and maintaining consistency in RIA measurements. [6]

9. Describe 5 of the following immunochemical techniques:
9.1 Radial Immunodiffusion
9.2 Immunoelectrophoresis
9.3 Isoelectric focusing ( IEF )
9.4 Western blot
9.5 Laurell ‘Rocket’ immunoelectrophoresis
9.6 Immunonephelometry
[10]


Additional information:

Molar mass:
K 39 Cl 35.5 H 1 S 32 O 16 Na 23


H2SO4 (sp gr = 1.84g/mL; assay = 97%)