Studies on silica biomineralization focus principally on marine sponges and diatoms. Diatoms are known to synthesise a silicified cell wall named “frustule” by intracellular transport and polymerisation of silicic acid Si(OH)4. Frustule is also composed of organic matter - mainly polysaccharides, proteins such as silaffins and long chain polyamines - that were already demonstrated to be capable of inducing silica polymerization into nanospheres of ca. 50-200 nm in diameter. In this context, solid-state Nuclear Magnetic Resonance (ssNMR) appears to be a powerful tool for studying the mineral-organics interactions in Thalassiosira pseudonana specimen. To do so, isotopically doubly-enriched (15N, 13C) T. Pseudonana were studied as whole cells, SDS-extracted and H2O2-cleaned samples by 1H, 13C, 15N, 29Si and 31P ssNMR through 1D and 2D experiments.