Untersuchungen zur genetischen Funktion des farblosen Plastiden vonPolytoma mirum

Ribosomal proteins from the chloroplast of Chlamydomonas reinhardii and two streptomycin‐resistant mutants

“…Isolation of crude ribosomes was performed according to SCHERBEL et al (1974); in addition they were once more purified by centrifugation for 20 min at 20 000 g and 0 C. For preparative separation of chloroplastic and cytoplasmic ribosomes, total ribosomes were layered on sucrose gradients (10-30%), containing 5 mM MgCl 2 , 25 mM KC1, 50 mM Tris-HCl ( p H 7.5), and 5 mM mercaptoethanol. Gradients were centrifuged for 14Vä h at 70 000 g and 2 C in a rotor SW 27 (Beckman L 2 50 B).…”