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  2. Molar absorption coefficient - Wikipedia

    en.wikipedia.org/wiki/Molar_absorption_coefficient

    c is the molar concentration of those species; ℓ is the path length. Different disciplines have different conventions as to whether absorbance is decadic (10-based) or Napierian (e-based), i.e., defined with respect to the transmission via common logarithm (log 10) or a natural logarithm (ln). The molar absorption coefficient is usually decadic.

  3. Absorbance - Wikipedia

    en.wikipedia.org/wiki/Absorbance

    Since the absorbance of a sample is measured as a logarithm, it is directly proportional to the thickness of the sample and to the concentration of the absorbing material in the sample. Some other measures related to absorption, such as transmittance, are measured as a simple ratio so they vary exponentially with the thickness and concentration ...

  4. Molar concentration - Wikipedia

    en.wikipedia.org/wiki/Molar_concentration

    The concentration of pure osmium tetroxide (molar mass = 254.23 g/mol) is c(OsO 4) = ⁠ 5.1 kg/L / 254.23 g/mol ⁠ = 20.1 mol/L. A typical protein in bacteria, such as E. coli, may have about 60 copies, and the volume of a bacterium is about 10 −15 L. Thus, the number concentration C is C = 60 / (10 −15 L) = 6 × 10 16 L −1. The molar ...

  5. Nucleic acid quantitation - Wikipedia

    en.wikipedia.org/wiki/Nucleic_acid_quantitation

    In essence, the Beer Lambert Law makes it possible to relate the amount of light absorbed to the concentration of the absorbing molecule. The following absorbance units to nucleic acid concentration conversion factors are used to convert OD to concentration of unknown nucleic acid samples: [5] A260 dsDNA = 50 μg/mL A260 ssDNA = 33 μg/mL

  6. Bradford protein assay - Wikipedia

    en.wikipedia.org/wiki/Bradford_protein_assay

    The equation displayed on the chart gives a means for calculating the absorbance and therefore concentration of the unknown samples. In Graph 1, x is concentration and y is absorbance, so one must rearrange the equation to solve for x and enter the absorbance of the measured unknown. [25]

  7. Determination of equilibrium constants - Wikipedia

    en.wikipedia.org/wiki/Determination_of...

    where l is the optical path length, ε is a molar absorbance at unit path length and c is a concentration. More than one of the species may contribute to the absorbance. In principle absorbance may be measured at one wavelength only, but in present-day practice it is common to record complete spectra.

  8. Enzyme assay - Wikipedia

    en.wikipedia.org/wiki/Enzyme_assay

    Static light scattering measures the product of weight-averaged molar mass and concentration of macromolecules in solution. Given a fixed total concentration of one or more species over the measurement time, the scattering signal is a direct measure of the weight-averaged molar mass of the solution, which will vary as complexes form or dissociate.

  9. Beer–Lambert law - Wikipedia

    en.wikipedia.org/wiki/Beer–Lambert_law

    Absorbance within range of 0.2 to 0.5 is ideal to maintain linearity in the Beer–Lambert law. If the radiation is especially intense, nonlinear optical processes can also cause variances. The main reason, however, is that the concentration dependence is in general non-linear and Beer's law is valid only under certain conditions as shown by ...