Bismuth nanocolloid or BIT refers to organic bismuth encapsulated in phospholipid core for use as a contrast agent. The Ocean NanoTech’s bismuth nanocolloid (BIT) can be used as a contrast agent for imaging modalities like Spectral computed tomography (CT), CT and X-ray. The BIT offers higher content of bismuth per nanocolloid due to our unique preparation method. This nanocolloid is compatible with various buffers and cell culture media. The zeta potential of plain BIT is around -20- -30 mV indicating good colloidal stability.