BIO RAD SmartSpec 3000 Instruction Manual page 53

III. DNA and RNA Oligonucleotide Concentration:
• Concentration = A/(εb) * 10
• Concentration = A/(εb) * MW * 10
where A = absorbance, ε = molar extinction coefficient in liter/mole/cm,
b = pathlength in cm and MW = molecular weight.
For cuvettes with a 10 mm (1 cm ) pathlength, these equations simplify to:
• Concentration = A/ε * 10
• Concentration = A/ε * MW * 10
IV. dsDNA, RNA, ssDNA concentration:
• A * Conversion Factor * Dilution Factor = µg/ml concentration
260
OR
• (A - A ) * Conversion Factor * Dilution Factor = µg/ml concentration
260 320
Default conversion factors are:
1.0 O.D. unit = 50 µg/ml dsDNA concentration
1.0 O.D. unit = 40 µg/ml RNA concentration
1.0 O.D. unit = 33 µg/ml ssDNA concentration
A /A ratios are 1.8 and 2.0 for pure DNA and RNA preparations, respectively.
260 280
V. Quantitating UV-proteins:
Protein (mg/ml) = 1.55 * (A
Coefficients 1 and 2 (defaults 1.55 and 0.76, respectively) can be changed for different proteins.
VI. Cells/ml:
Cells/ml = A600 * Conversion Factor * dilution factor
Default conversion factor is 5 x 10
6
pmole/µl
3
µg/ml
6
pmole/µl = (µg/ml)* (1000)/MW
3
µg/ml = (pmol/µl) * (MW)/1000
– A ) – 0.76 * (A -A
280 320 260
8
cells/ml
50
)
320