Researchers compare three fluorescently labelled monoclonal antibodies to locate cells carrying antigen Q. They measure fluorescence from samples of cells known to carry antigen Q and cells known not to carry antigen Q. The same concentration of each antibody is used under the same conditions.
| Antibody | Fluorescence from cells carrying antigen Q (relative fluorescence units) | Fluorescence from cells not carrying antigen Q (relative fluorescence units) |
|---|---|---|
| X | 92 | 8 |
| Y | 45 | 40 |
| Z | 10 | 7 |
Explain which antibody should be chosen to locate cells carrying antigen Q and how the results support this choice.
87 exam-style questions on Edexcel GCSE Biology 5.3 Immune system and medicines, covering 5.3.1 The specific immune system, 5.3.2 Response to immunisation, 5.3.3 Advantages and disadvantages of immunisation, 5.3.4 Antibiotics and bacterial infections, 5.3.5 Aseptic techniques in culturing, 5.3.6 Cross-sectional areas of cultures, 5.3.7 Stages of developing new medicines, and 5.3.8 Production of monoclonal antibodies. Each one has a worked solution and a mark scheme showing where the marks go.