Chinese researchers claim to have invented an inexpensive point-of-care (POC), paper-based blood test that can determine a patient’s blood type in seconds and with nearly perfect accuracy.
"In our proof-of-concept experiment, we used the rapid reaction between albumin and BCG [bromocresol green dye] to substantially reduce the analytical time without compromising specificity and sensitivity," the researchers wrote in the study.
Dye-assisted paper-based test strips use immobilized antibodies and green dye for rapid and reliable blood grouping. A visual readout that changes colors reveals the different blood types. A teal square appears if an antigen is present, while a brown square appears if it is not.
When tested on 3,550 human blood samples the assay was 99.9% accurate. ABO antigens and five major Rh antigens could be detected within 30 seconds. More rare blood types were determined in less than two minutes without centrifugation.
The low-cost assay would be a boon in remote areas, war zones, and emergency departments by providing fast and reliable blood typing without the need for specialized clinical lab equipment, and by reducing demand on type-O blood supplies.