What techniques were employed in the 'Calvin Experiment' to elucidate the carboxylation of RuBP (IB-HL 8.3)?

Calvin carried out ‘feeding experiments’ where radioactive labelled carbon was fed to plants. ¹⁴CO₂ is taken up the cells and is then fixed into photosynthesis. ¹⁴CO₂ was induced into the plants and monitored. Samples of photosynthesising cells taken at frequent intervals after feeding contained a sequence of radioactively labelled intermediates and products of the photosynthetic pathway. They were then isolated by chromatography. Chlorella was used, instead of mesophyll tissue, because they are easy to sample and have identical photosynthesis pathways