Abstract: A method and system for writing a label (defined within a predetermined region of the sample 110), the label displaying a visible layout of light-modified regions in a predetermined spatial arrangement. The method comprises: modifying regions of a material within the label using light, wherein the modifying comprises using light of a first polarisation state to provide photo-induced optically active regions of a first type having a first optical activity state which is characteristic of having been formed by light of the first polarisation state, in order to encode covert information in the label using the locations of the first type of light-modified regions within the spatial arrangement of the label.

Abstract: A method and system for writing a label (defined within a predetermined region of the sample 110), the label displaying a visible layout of light-modified regions in a predetermined spatial arrangement. The method comprises: modifying regions of a material within the label using light, wherein the modifying comprises using light of a first polarisation state to provide photo-induced optically active regions of a first type having a first optical activity state which is characteristic of having been formed by light of the first polarisation state, in order to encode covert information in the label using the locations of the first type of light-modified regions within the spatial arrangement of the label.

Abstract: An exogenous pharmaceutical preparation in which a lipid tagged bioactive material is combined with albumin is disclosed. The albumin has a low proportion of lipidic/fatty acid groups (a molar ratio of fatty acid groups to albumin of less than 0.7) and is preferably fatty acid free. The albumin may be naturally extracted such as Human Serum Albumin or recombinantly produced. A range of bioactive substances, such as peptides, proteins or vaccines may be tagged and combined with albumin for human, veterinary or agricultural use. Several antimicrobial peptides are disclosed. Binding to the albumin mediates the biostability of the tagged bioactive material. Due to this stabilization, the antimicrobial activity of a model lipopeptide is enhanced when combined with substantially fatty acid free-albumin. When bound to albumin, therefore, the model lipopeptide exerts an antimicrobial effect at a lower concentration than the model lipopeptide alone.