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«« Back to Applications
Protein Applications
Protein UV
The Protein UV method determines Proteins at 280nm.
The effect of nucleic acid in the protein solution due to strong nucleotide absorbance at 280 nm can be compensated by measuring Abs 260, and following the equation of Christian Warburg:
Protein (mg/ml) = 1.55*A280 - 0.76* A260
The use of background correction at 320 nm is optional.
Protein Dye
The Protein Dye method determines proteins at 280 nm as well as dye incorporation. Common dye types are preprogrammed for convenience or a custom dye can be specified from 190-1100nm.
BCA
The BCA method depends on reaction between Cupric ions and peptide bonds, but in addition combines this reaction with the detection of Cuprous ions using bicinchoninic acid (BCA), giving an absorbance maximum at 562 nm.
The BCA process is less sensitive to the presence of detergents used to break down cell walls.
Select units of measurement:
µg/µl, pmol/µl, µg/ml, mg/ml, µg/l, mg/l, g/l, mmol/l, µmol/l, U/l, %, ppm, ppb, conc, none.
Calibration mode:
Either measurements of prepared standards or manually enter data via keypad.
The Calibration Screen shows the calibration values and allows standards to be measured. A graph will display the results and the fitted curve as measurements are made. Poor reading can be repeated (with replicates on).
Bradford
The Bradford method depends on quantitating the binding of a dye, Coomassie Brilliant Blue, to an unknown protein and comparing this binding to that of different, known concentrations of a standard protein at 595 nm (default setting); this is usually BSA, bovine serum albumin.
Select units of measurement:
µg/µl, pmol/µl, µg/ml, mg/dl, µg/l, mg/l, g/l, mmol/l, µmol/l, U/l, %, ppm, ppb, conc, none.
Calibration mode:
Either measurements of prepared standards or manually enter data via keypad
The Calibration Screen shows the calibration values and allows standards to be measured. A graph will display the results and the fitted curve as measurements are made. Poor reading can be repeated (with replicates on).
Lowry
The Lowry method depends on quantifying the colour obtained from the reaction of Folin-Ciocalteu phenol reagent with the tylsryl residues of an unknown protein and comparing with those derived from a standard curve of a standard protein at 750nm; this is usually BSA, bovine serum albumin.
Select units of measurement:
µg/µl, pmol/µl, µg/ml, mg/dl, µg/l, mg/l, g/l, mmol/l, µmol/l, U/l, %, ppm, ppb, conc, none.
Calibration mode:
Either measurements of prepared standards or manually enter data via keypad
The Calibration Screen shows the calibration values and allows standards to be measured. A graph will display the results and the fitted curve as measurements are made. Poor reading can be repeated (with replicates on).
Biuret
The Biuret method measures the reaction between Cupric ions and peptide bonds in an alkali solution, resulting in the formation of a complex absorbing at 546 nm.
Select units of measurement:
µg/µl, pmol/µl, µg/ml, mg/dl, µg/l, mg/l, g/l, mmol/l, µmol/l, U/l, %, ppm, ppb, conc, none.
Calibration mode:
Either measurements of prepared standards or manually enter data via keypad
The Calibration Screen shows the calibration values and allows standards to be measured. A graph will display the results and the fitted curve as measurements are made. Poor reading can be repeated (with replicates on).
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