Triplet  binding  assay.  Ribosomes  can  bind to three-ribonucleotide
   sequences  (codon)  in  vitro,  which  in turn bind to a complementary
   anticodon within tRNA carrying a specific, radioactively charged amino
   acid.

   The  whole  complex can be bound to nitrocellulose filter, and assayed
   for the charged amino acids.