sb-PEPTIDE offers to determine precisely the quantity of your peptides. Various methods can be used for quantifying peptides such as 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 (TFA or acetate salts that represent more than 10% of the amount usually) used during the purification and 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 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) which 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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