NI Assays: Troubleshooting & Analysis of Curve Fitting Graph 1: Standard clinical isolate Good NA activity S shaped curve (observed points) IC50 in expected

NI Assays: Troubleshooting & Analysis of Curve Fitting

Graph 1: Standard clinical isolate• Good NA activity• S shaped curve (observed points)• IC50 in expected range for susceptible B • Good fit of calculated curve to observed pointsConclusion: VALID sensitive isolate


Graph 2: Known resistant mutant• Low NA activity• Known resistant virus• High IC50• S shaped curve, but displaced right because of drug inhibition• Good fit curve to observed pointsConclusion: VALID resistant isolate


Graph 3: Clinical isolate with low IC50• Low NA activity• Poor fit observed points to calculated curve• IC50 value lowConclusion: Probably isolate with normal IC50 → REPEAT


Graph 4: Clinical isolate with high IC50• Low NA activity• Poor fit observed points to curve• IC50 displaced to right• High IC50Conclusion: Probably resistant isolate REPEAT to check


Graph 5: Clinical isolate with low IC50• Good NA activity• Poor fit observed values to curve especially at high drug concentrations• Non sigmoidal shape of observed curve• Low IC50Conclusion: Probable error drug dilution for normal iC50 invalid →

REPEAT


Graph 6: Clinical isolate with high IC50• Low NA activity• Non sigmoidal observed points• High IC50• Bimodal distribution observed points• Poor fit between observed points and curveConclusion: Possible resistant but technical errors → REPEAT


Graph 7: Clinical isolate with normal IC50• Good NA activity• Increase in drug concentration associated with increase NA activity

(Biologically implausible)• Non sigmoidal observed points• Poor fit observed points and curveConclusion: Invalid analysis but probably normal IC50. Technical

errors → REPEAT


Graph 8: Clinical isolate with low IC50• Low NA activity• Increase NA activity with drug concentration (Biologically implausible)• Bimodal distribution observed points• Poor fit observed points to curve• Low IC50Conclusion: INVALID analysis → REPEAT as probably normal IC50


Graph 9: Clinical isolate with low IC50• Good NA activity • NA activity increases with drug concentration• Bimodal distribution observed points• Poor fit curves and observed points• Low IC50Conclusion: Invalid analysis → REPEAT as probably normal IC50

Documents

NI Assays: Troubleshooting & Analysis of Curve Fitting Graph 1: Standard clinical isolate Good NA activity S shaped curve (observed points) IC50 in expected