The increasing pace of development in molecular biological techniques during the last 10-15 years has had a direct effect on mass testing and diagnostic applications, including blood screening. Nucleic acid amplification techniques (NAT), usually based on the polymerase chain reaction (PCR), have been successfully applied to blood grouping and implemented recently in screening of blood donations for hepatitis C virus (HCV). The majority of microarray technologies involve an amplification step, yet the main benefits of this technology come from simultaneous analysis of thousands of analytes. Microarrays were developed to utilize the huge amount of information provided by genome projects, but they have clear potential in mass screening and diagnostics. The application of microarray technology may revolutionize blood testing, providing for the first time the prospect of an integrated platform for comprehensive donor and donation testing, replacing multiple individual assays. Design features of a blood-testing chip and various technologies with potential application in this field are discussed in this review.