Rapid and reliable POCT blood typing based on laser identified RBC agglutination method

Abstract

Blood typing is a critical element of medical diagnostics and health assessment. Nevertheless, prevailing point-of-care testing (POCT) assays, including the slide method, tube method, column agglutination method, and gel test method, often necessitate costly equipment such as centrifuges, cumbersome procedures, and skilled personnel for operation. And the testing time is relatively long (~30 min), which is not applicable in emergency cases/point-of-care testing. Thus, a low-cost, simple, low blood consumption and rapid blood typing method are urgently required, especially in the resource limited areas for point-of-care applications. We present a novel method of laser identified RBC agglutination reaction to achieve accurate and reliable blood typing. Specifically, the RBC agglutination reaction (a bio-signal) is firstly converted into a laser signal (a laser beam passed or not). Subsequently, a photoresistor converts the laser signal into a specific electrical signal (a high resistance or a low one). Finally, the electrical signal is converted to an optical signal through a detection circuit (if the resistance is lower than 600 Ω, resulting in the opening of an LED light; otherwise, the LED light is off). By merely interpreting the light signals, even non-professionals can precisely determine the blood types without any risk of misinterpretation. This laser-based blood typing method can effectively avoid human errors caused by naked-eye observation or environmental interference, and can provide new insights for developing accuracy and reliability hemagglutination identification methods for POC blood typing.