Real lab failures, root causes, and fixes — curated and bilingually annotated by our team.
The regression coefficient (R²) of the standard curve falls below 0.98, indicating poor curve fit and unreliable quantification of sample concentrations.
The optical density (OD) measurement values for the standard curve vary considerably from the examples shown on the kit datasheet or protocol booklet, causing user concern about assay validity.
Standard curve shows irregular pattern or non-monotonic response, with individual points deviating significantly from expected sigmoidal or linear trend.
After adding reconstitution buffer to lyophilized standard, visible undissolved material or particulates remain in the vial, leading to inaccurate standard concentrations.
The recommended curve-fitting model (typically Four-Parameter Logistic) does not adequately fit the standard data points, resulting in poor correlation even with properly prepared standards.
Duplicate or triplicate wells for the same standard concentration show high variability (CV >10-15%), compromising curve fit and confidence in quantification.
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