Three peptides that corresponded to the amino acid sequence of the second extracellular loop of human β1-, β2-, and α1-AR were synthesised by Genomed (Genomed Synthesis, Inc., CA, USA). The sequences are presented in Table 1.[17] (link)–[19] (link) The peptide was judged to be pure on the basis of a HPLC analysis on a Vydac C-18 column and via an amino acid analysis on an automated amino acid analyser (Beckman Instruments, Inc., Palo Alto, CA).[20] (link)