A2439C Laboratory Management and Operations Assignment Questions 2025 | RP

Question 1 [13 marks]

Purified protein sample ‘X’ was used to plot a standard curve for an assay to measure antibodies in patients’ blood samples. Sample ‘X’ was serially diluted, and absorbance was measured for each concentration (Table 1).

a) Why was a ‘0’ concentration of stock solution used in this test (last row)? Justify your answer. [3 marks]

b) Using the data from Table 1, plot a standard curve. [7 marks]

c) A patient’s blood sample was diluted 100 times, and it produced an absorbance reading of 0.5. What is the concentration of antibody in the patient’s blood? [3 marks]

Question 2 [10 marks]

Test A is a gold standard method to determine disease ‘X’. Two other new test methods, B and C, were compared with Test A. A method evaluation was done using Bland-Altman plots. The graphs are shown below.

a) Analyse the charts plotted and conclude if the new tests (Test B and C) are suitable to replace the gold standard (Test A). Provide relevant justifications for your conclusion. [6 marks]

Figure 2: Bland-Altman Plot showing the comparison between Test A and C

b) It is reported that Test A has a sensitivity of 98% and a specificity of 75%. Is Test A more suitable to be used as a screening test or as a confirmatory test? Justify your answer. [4 marks]

Question 3 [17 marks]

The following video shows the features of an automated slide stainer.

Laboratory XYZ decided to purchase this slide stainer.

A. Outline the steps required to conduct a break-even analysis for these instruments. Discuss the importance of conducting break-even analysis before purchasing such devices. [4 marks].

B. State TWO analytical errors that might occur while using this instrument. Could you explain how to minimise them? [4 marks]

C. Identify THREE work activities and draft a Hazard Identification and Risk Assessment (HIRA) document for the automated slide stainer. Please use the template provided below. [9 Marks]