对数中期培养物:OD600 0.5 → 5×10⁸ cells/mL、0.18 g/L 干重 未稀释的对数中期 E. coli 培养物在 1 cm 比色皿中读得 OD600 = 0.5。按默认系数即 0.5 × 1×10⁹ = 5×10⁸ cells/mL、0.5 × 0.36 = 0.18 g/L 细胞干重;整瓶 25 mL 共 1.25×10¹⁰ 个细胞 ≈ 4.5 mg 干重。换算得单细胞干重 0.36 pg——E. coli 对数中期的经典数值。{"result":"OD600 0.5 → 500000000 cells/mL, 0.18 g/L CDW; 25 mL holds 12500000000 cells (0.0045 g).","metadata":{"input":{"od600":0.5,"dilutionFactor":1,"pathLengthCm":1,"cultureVolumeMl":25},"result":{"od600Normalized":0.5,"cellsPerMl":500000000,"totalCells":12500000000,"cdwPerLiterG":0.18,"cdwTotalG":0.0045,"cellDryWeightPg":0.36}}}
1:10 稀释的稳定期样品:读数 0.25 → 真实 OD 2.5 并标记 稳定期后期的培养物经 1:10 稀释后读得 OD600 = 0.25,因此 1 cm 光程下的真实值为 0.25 × 10 = 2.5——已超过约 1.0 的线性上限,工具会予以标记。即便如此仍可估算 2.5×10⁹ cells/mL 与 0.9 g/L 干重,同时建议加大稀释倍数以获得准确读数。未填培养物体积,故跳过总量。{"result":"OD600 2.5 → 2500000000 cells/mL, 0.9 g/L CDW; reading above linear range — dilute further.","metadata":{"input":{"od600":0.25,"dilutionFactor":10,"pathLengthCm":1,"cultureVolumeMl":0},"result":{"od600Normalized":2.5,"cellsPerMl":2500000000,"totalCells":null,"cdwPerLiterG":0.9,"cdwTotalG":null,"linearity":"above linear range (OD > 1) — dilute further before reading"}}}