Method of identifying a structure

A method of feature differentiation in a biological sample wherein the feature potentially has compromised or atypical morphology;

• the method including:
• providing a sample holder comprising a substrate and having an upper surface and a lower surface, the upper surface having a plasmonic layer associated therewith, the plasmonic layer supported by the substrate and including a periodic array of sub-micron structures;
• applying the biological sample to the upper surface of the sample holder;
• illuminating the sample with light so that said light interacts with the sample and the sample holder;
• forming an image using said light, after interaction with said sample and said sample holder, wherein at least one localised structural property of the biological sample is visible in the image based on the colour of received light to thereby enable the feature to be differentiated from its surroundings based on its colour in the image;
• wherein the sample is thicker than a characteristic decay length of the plasmonic layer, and/or the sample is substantially transparent.

A method of identifying a sign of cancer in a sample, comprising;

• providing a sample holder comprising a substrate and having a plasmonic layer supported by the substrate including a periodic array of sub-micron structures;
• placing the sample on the sample holder adjacent the plasmonic layer;
• illuminating the sample and the sample holder and forming an image thereof to enable a structure in the sample to be visualised, wherein the image exhibits spatial colour contrast in the image of the sample depending on the localised dielectric constant of the sample;
• identifying one or more features of the sample in the images at least partially based on the colour of the feature;
• and
• determining if one or more characteristics of the feature are a sign of cancer;
• wherein the sample is thicker than a characteristic decay length of the plasmonic layer, and/or the sample is substantially transparent.

A method of determining a state of at least one cell in a sample, the method including:

• providing a sample holder comprising a substrate and having a plasmonic layer supported by the substrate including a periodic array of sub-micron structures;
• placing the sample on the sample holder adjacent the plasmonic layer;
• illuminating the sample and the sample holder and forming an image thereof to enable a structure in the sample to be visualised, wherein the image exhibits spatial colour contrast in the image of the sample depending on the localised dielectric constant of the sample;
• and
• determining a state of at least one cell based at least partially based on the colour of the at least one cell in the image;
• wherein the sample contains a plurality of cells of the same type and the method includes distinguishing at least one cell from cells of the same type based on a colour contrast between the at least one cell and cells in the plurality of cells.

A method of determining a state of at least one cell in a sample, the method including:

• providing a sample holder comprising a substrate and having a plasmonic layer supported by the substrate including a periodic array of sub-micron structures;
• placing the sample on the sample holder adjacent the plasmonic layer;
• illuminating the sample and the sample holder and forming an image thereof to enable a structure in the sample to be visualised, wherein the image exhibits spatial colour contrast in the image of the sample depending on the localised dielectric constant of the sample;
• and
• determining a state of at least one cell based at least partially based on the colour of the at least one cell in the image;
• wherein the sample is thicker than a characteristic decay length of the plasmonic layer, and/or the sample is substantially transparent.