Here is one of the many protocols from Pestova`s lab, an world expert in ribosome functioning and translation:

Pestova T.V., Hellen, C.U.T., and Shatsky, I.N. 1996. Canonical eukaryotic initiation factors determine initiation of translation by internal ribosomal entry. Mol. Cell. Biol. 16: 6859-6869.

thank you, but i want some detailed protocols that used in laboratory, i have found some paper each has different methods, and i did not find articles that introduce what kind of contamination usually appear and how to validate the purity.

In the following reference, you will find precise and elaborate protocols how to obtain highly pure ribosomes and how to analyse them. The article is available here on RG. Hope this helps...

Best regards,

John

Blaha, G., U. Stelzl, C. M. Spahn, R. K. Agrawal, J. Frank and K. H. Nierhaus (2000). "Preparation of functional ribosomal complexes and effect of buffer conditions on tRNA positions observed by cryoelectron microscopy." Methods Enzymol 317: 292-309.

https://www.researchgate.net/publication/236963691_Preparation_of_Functional_Ribosomal_Complexes_and_Effect_of_Buffer_Conditions_on_tRNA_Positions_Observed_by_cryoelectron_microscopy?ev=prf_pub

Article Preparation of Functional Ribosomal Complexes and Effect of ...