Heart disease is the leading cause of mortality in the western world and improvements in the early diagnosis of cardiovascular disease (CVD) can have a major impact on patient prognosis. Molecular-based technologies have given scientists the ability to generate antibodies from virtually any species with exquisite specificities and highly tailored biophysical properties. Avian reagents represent a novel approach that is well suited for human diagnostic development, as the distinct features of the avian immune system offer advantageous properties including stronger immune response to human proteins, greater antibody diversity and improved antibody stability. This is in tandem with improved assay performance parameters such as, reduced interference and incidences of false positives (no heterophile or HAMA responses) ^{1, 2} . The ability to acquire large amounts of data relating to binding events, in a high-throughput (HT) manner, underpins the successful selection of truly superior antibodies. In such a HT selection campaign an epitope-specific, ultra­-high affinity, single chain antibody (scFv) was isolated from a Gallus Gallus immunised repertoire. The isolated clone was subsequently shown to be superior to the equivalent industry standard antibody for the CVD gold standard biomarker, cardiac troponin I (cTnI) ³ . To gain an insight into the mechanism of the antibody interaction, large-scale crystallisation trials were undertaken at Monash’s crystalmation suite. From an initial screen of 576 conditions and a grid screen of 96 additives, single crystals were obtained. Crystals were diffracted at the Australian Synchrotron, on the finely focussed MX2 beamline, and the 1.35Å structure determined.