Peptide quantification

SB-PEPTIDE offers peptide quantification. Indeed, SB-PEPTIDE is able to determine precisely the quantity of your peptides. Various methods can be used for quantifying peptides. For example, measurement at 280 nm in solution when applicable, weighing peptide as powder or amino acid analysis method.

The method of weighing dried peptides is not accurate because of the presence of counterions. Counterions can be TFA or acetate salts that represent more than 10% of the amount usually. These salts are used during the purification and in atmospheric water. The peptide quantity measured by weighing is named gross weight. Depending on the amino acid sequence, the net peptide content (quantity of peptidic material) can be below 50%.

Quantification by optical density measurement at 280 nm is more accurate. But this method can only be applied on peptides containing aromatic residues (Tyr, Phe, Trp).

The gold standard method to quantify a peptide is the amino acid analysis (AAA). Indeed, it gives the exact NPC (net peptide content) of a sample. SB-PEPTIDE offers to perform AAA analysis for determining the exact quantity of its client’s peptides.

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