Abcam biochemical peptides are supplied either by net or gross weight, which will be indicated on the Certificate of Analysis accompanying the product. While peptides for research use are typically > 95% pure by HPLC, the peptide content of the solid may typically range from 70 to 90% as peptides contain counter ions (e.g. acetate, trifluoroacetate) and residual moisture. The peptide content of each batch is shown on the Certificate of Analysis that accompanies each product.
Net peptide weight: For those peptides supplied by net peptide weight, these are weighed so that the amount of peptide received is exactly that stated on the vial. The actual amount of solid present in the vial will be dependent on the peptide content.
Gross weight: For those peptides supplied by gross weight, it is important that peptide content is taken into consideration. The peptide content is determined by amino acid analysis and is typically 70-90%. The net peptide weight is calculated by multiplying the peptide content by the gross weight. For example, a sample of peptide with gross weight of 5 mg and peptide content of 85% has a net peptide weight of 4.25 mg (5 mg x 0.85).