An important area of experimental stroke research addresses the development of brain hemorrhage after cerebral ischemia. Investigations of hemorrhagic transformation, however, have been compromised by the absence of sensitive methods for quantification of hemorrhagic transformation. We have developed a direct ELISA method that is sensitive, reproducible and can be conducted on tissue treated with triphenyltetrazolium chloride, a stain commonly used for infarct size determination. We have also localized the slices containing the most hemoglobin to facilitate a single slice analysis. This allows two essential variables in experimental stroke research to be assessed on the same slice, leaving the rest of the brain available for other analysis.