Purpose: The aim of the work described in this thesis was to determine whether needle core and open biopsies from osteosarcoma (OS) provide sufficient quality of mRNA for cDNA array analyses which might then provide insights into the expression profile of OS. Experimental Design: Sixteen samples collected from OS and two established cell lines were used for array analyses. A primary cell culture was also established from one of the OS biopsies. Total RNA was extracted and probes generated for cDNA arrays. A reference probe was included for computational analyses. Results: cDNA probes were made for twenty five samples. Two of these samples were needle core bone biopsies. Twenty two cDNA probes were used for the generation of microarray data. Previous established statistical analysis confirmed the reliability of array data obtained in sixteen of the twenty two samples. Known genes involved in bone metabolism, osteoblast differentiation and cancer cell growth, were identified as up- or down-regulated in OS. Conclusions: Without amplification of RNA, OS tissue including small core bone biopsies, are amenable to cDNA array analysis. Known and novel putative markers for OS, that could have prognostic value, were identified.