Ribosome-nascent chain complex
Ribosome-nascent chain complex (RNC) refers to the collection of molecules that constitute a ribosome attached to the polypeptide (protein) that it is synthesising. The synthesis of the nascent polypeptide may be stalled by one of several methods. RNCs are produced and purified in laboratories to study the dynamics, biochemistry, folding and interactions of both the ribosome and proteins undergoing synthesis. References 

Protein complexes
Protein biosynthesis