Several proteins have been found in large aggregates, amyloid, with highly similar cross beta structure. The aggregating segment is often part of a larger peptide of protein with rather wide tolerance for amino acid sequence and native structure. We investigate the aggregation process and the influence of intrinsic (sequence) and extrinsic (solution conditions, lipid membranes, additives, other proteins, etc.) factors. We have developed highly efficient expression and purification systems for several amyloid proteins, including amyloid beta peptide from Alzheimer’s disease. We have achieved unforeseen reproducibility of kinetic assays and found that amyloid formation follows the behavior as expected of a phase transition. The use of a clean system with no cosolvents has allowed us to observe the retarding effects of phospholipid membranes. We study coaggregation between lipids and amyloid proteins in different stages from monomer to large fibrillar aggregates. For intermediate stages our emphasis is on the process rather than specific transient species along the pathway. The high reproducibility we have achieved allow us to study samples at well-defined stages along the pathway to represent a mixture of all transient species present at that tie point.