We use Isothermal Titration Calorimetry (ITC) for studying translational GTPases for quite some time now, and it turnes out one can do one more translation-related things with it: measure thermodynamics of subunit association with it (Osterman Biochimie 2011).
Quite amazing, actually. Sample is mixed at 200 rpm, ∼2 μM 50S are titrated with ∼11 μM 30S subunits, and yet seemingly there are no problems with precipitation and heat generated by it.
I would suspect that this means that one can follow initiation complex formation too...
Ilya A Osterman, Petr V Sergiev, Philipp O Tsvetkov, Alexander A Makarov, Alexey A Bogdanov, Olga A Dontsova. Methylated 23S rRNA nucleotide m(2)G1835 of Escherichia coli ribosome facilitates subunit association. Biochimie 2011 PIMD 21237242