Bio-Rad ChromLab™ Software - Manual (Page 246)

7 | Evaluating Results
244 | NGC Chromatography Systems and ChromLab Software
 Extinction coefficient ((mg/ml)
-1
cm
-1
) — the extinction coefficient of the
protein, used to calculate the protein concentration. ChromLab
automatically populates this field when the extinction coefficient is entered
or changed in the Peaks table.
Note: Changing a single coefficient in the Peaks table affects only
coefficients for the fractions that contain that peak.
 Molecular mass (kDa) — the molecular mass of the protein. By default
this field is empty. Molecular mass values that you enter in the Peaks table
are automatically populated to the Fractions table for relevant fractions.
Molecular mass values that you enter in the Fractions table are
not
automatically populated to the Peaks table.
 Molarity (
M) — the calculated molar concentration of the protein for the
specified peak. This value is computed from the calculated concentration
and molecular mass.
 280/260 (or 280/255) — the ratio of average absorbance at 280 nm and
260 nm (or 255 nm) used to determine the purity of protein for each
fraction. The ratio appears in the 280 nm trace section of the table. The
ratio is calculated using baseline subtracted values of the UV traces area
within the fraction.
Note: The column appears after Peak Integration is performed when both
the 280 nm and 260 nm (or 255 nm) traces are detected. Depending on
which trace is present, the column name can be either 280/260 or 280/255.