Osteogenesis Imperfecta (OI) is a genetic disorder that impacts the strength of an individuals bones due to defective collagen. OI, also referred to as brittle bone syndrome is commonly caused by a mutation in the COL1A1 OR COL1A2 genes coding for the ?1 and ?2 collagen proteins. The aim of this investigation was to compare a control sample of collagen secreted fibroblasts with a patient with a suspected OI. It was suggested that the collagen from the OI suspected individual would be larger and therefore would have slower mobility than the control fibroblasts. The skin fibroblasts were immersed in ascorbic acid to stimulate collagen production. Pepsin was then added to the procollagen proteins extracted from the culture medium to remove the non-helical sequences from the protein. SDS-PAGE electrophoresis on a 7.5% acrylamide gel was used to separate the collagen. There were no ?1 or ?2 chains (95kDa and 92kDa) present within either of the samples. Short collagen sequences were present at 75kDa and 55kDa in the patient sample and 70kDa and 50kDa in the control sample. A conclusive statement cannot be made regarding to the diagnosis of OI on the individual because of the low resolution of the gel and therefore further testing using genetic sequencing is required.