In this issue of Biochemical Society Transactions, Elliott and Jones review some of the techniques used to prepare, measure and analyse the electron transfer properties of metalloproteins, concentrating on scanning tunnelling microscopy-based techniques and advances in attachment of proteins to electrodes. The cover image, taken from Figure 2 in the review, shows the direct attachment of a protein (cytochrome b₅₆₂) to gold substrate through an engineered cysteine residue. For further information see pages 1–9.