Abstract: A competitive binding assay kit and process for the immunological detection of a blood antigen of specified phenotype (for example phenotypes of human platelet antigen HPA) in a sample of whole blood. The kit contains a substrate having purified blood antigen of specified phenotype immobilized thereon, antibody specific to said blood antigen and means for enabling detection of antibody bound to said blood antigen. The process comprises mixing a sample of whole blood with a predetermined amount of antibody, so as to bind the antibody to any antigen present in the sample of whole blood and bringing the mixture into contact with the immobilized antigen so as to bind any remaining unbound antibody to the immobilized antigen, and determining the amount of immobilized complex and consequently the specified blood antigen phenotype.

Abstract: Haematopoietic stem cells (which term includes early progenitor cells) are immobilized on a substrate coated with a fibrin matrix and including a substance capable of both binding to the fibrin matrix and also having an RGD amino acid sequence for binding to the stem cells. The substance may be fibronectin or thrombospondin. The substrate is generally in the form of a closed bag formed of a carbon dioxide-permeable and oxygen-permeable plastics material which allows culturing of the stem cells. The cultured stem cells may re-engraft a patient following chemotherapy or to correct haemotological deficiencies. Stem cells may be harvested from peripheral blood onto the coated substrate. The stem cells in contact with the coated substrate are good candidates for gene therapy to introduce a heterologous gene e.g. employing a transfection vector.