Software Manual

7 | Evaluating Results

244 | NGC Chromatography Systems and ChromLab Software

 Extinction coefficient ((mg/ml)

-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

coef

ficients 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 ar

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 pr

esent, the column name can be either 280/260 or 280/255.