质粒小提:A260 = 0.25 的 1:10 稀释 dsDNA 1:10 稀释的质粒小提样品在标准 1 cm 比色皿中测得 A260 = 0.25。浓度 = 0.25 × 10 × 50 ÷ 1 = 125 µg/mL,即 125 ng/µL 双链 DNA。100 µL 洗脱液共含 125 × 0.1 = 12.5 µg——典型的健康小提产量,且读数恰在 0.1–1.5 线性范围内。{"result":"dsDNA concentration = 125 µg/mL (125 ng/µL); total 12.5 µg in 100 µL.","metadata":{"input":{"a260":0.25,"dnaType":"dsDNA","dilutionFactor":10,"pathLengthCm":1,"sampleVolumeUl":100},"result":{"constantUgMlPerOd":50,"concentrationUgMl":125,"concentrationNgUl":125,"totalUg":12.5,"measurementQuality":"within linear range (0.1–1.5)"}}}
ssDNA 寡核苷酸制备:A260 = 1.8 提示需稀释 未稀释的单链 DNA 制备测得 A260 = 1.8——已超出线性范围约 1.5 的上限,检测器可能饱和,因此 1.8 × 1 × 33 ÷ 1 = 59.4 µg/mL 这一数值应进一步稀释后复测。本例展示了换用系数 33(而非 50)以及工具如何标记超范围读数,而不是默默采信。{"result":"ssDNA concentration = 59.4 µg/mL (59.4 ng/µL); reading above the linear range — dilute and re-measure.","metadata":{"input":{"a260":1.8,"dnaType":"ssDNA","dilutionFactor":1,"pathLengthCm":1,"sampleVolumeUl":0},"result":{"constantUgMlPerOd":33,"concentrationUgMl":59.4,"concentrationNgUl":59.4,"totalUg":null,"measurementQuality":"above linear range — dilute sample"}}}