Chromatography matrices including novel ligands based on the protein A of Staphylococcus aureus

An affinity chromatography matrix comprising a solid support with a ligand affinity chromatography comprising one or more C domains of Staphylococcus protein A (SpA) with the amino acid sequence shown in SEQ ID NO .: 4 or encoded by the nucleotide sequence shown in SEQ ID NO .: 10, wherein at least one of the one or more domains C is mutated to delete 3, 4 or 5 consecutive amino acids from the N, starting at position 1 or position 2 of SEQ ID NO: 4 and the last amino acid of the C of at least one of the one or more domains C is a lysine at position 58 of SEQ ID NO: 4; wherein the ligand has a reduced fragmentation when bound to the solid support, relative to a ligand without deletions or equivalent wt after exposure to 0.5M NaOH for 5 hours.