In the field of molecular analysis of cancer, there exists a need for a clinical device that can automate protocols for immunohistochemical and in situ hybridization diagnostic staining on tissue microarrays. The tissue microarray antibody spotter (TMAS) has been developed to provide fundamental improvements over current histological staining techniques by enabling precision application of reagents to individual biopsies within a tissue microarray. This allows for multiplexed reactions on a single slide and promises to significantly reduce costs associated with immunohistochemistry and in situ hybridization based assays. Additionally, because TMAS allows for testing of different biomarkers on each element of a tissue array, a complete cancer profile can be obtained from a single TMA slide. Ultimately this may lead to cost-effective, faster and more accurate diagnosis of the patient.