β1,3-d-glucan particles were purified from baker’s yeast by a series of alkaline and solvent extractions, hydrolysing outer cell wall and intracellular components and yielding purified, porous 2–4 µm, hollow β1,3-d-glucan particles (diagram of particles, left; procedure, middle; microscopy of particles, right). Empty β1,3-d-glucan particles were then labelled with fluorescein (FL, green). The cores were synthesized by absorbing yeast tRNA, PEI and Dy547-labelled siRNA (red) in a layer-by-layer format. Bottom right: confocal image of a synthesized GeRP.