Ultrasound-enhanced Particle Agglutination (UPA) is a platform technology in which ultrasound is used to improve the performance of conventional particle agglutination immunoassays. UPA improves conventional particle agglutination and haemagglutination assays, by increasing sensitivity, decreasing incubation times, lowering reagent costs and delivering more quantitative results.

Other ultrasound-based technologies have been applied to the conventional particle agglutination assay in the past, but ALLIS technology is superior because UPA both enhances specific agglutination and decreases non-specific aggregation in a one-step procedure. In addition, ALLIS system provides for quantitative assessment of aggregates using simple optical means while samples remain in the resonator cell. These innovations allowed us to develop a one-step sensitive, simple and rapid method for detection of various physiologically active substances such as proteins (antigens or antibodies), bacteria and cells. Since UPA offers crucial advantages over other rapid tests, we believe that our Ultrasound-enhanced Particle Agglutination technology has great potential to meet the need for Point-of-Care (POC) sensitive diagnostics in media including food, environmental and clinical samples.

As a platform technology, UPA presents a general approach for the enhancement and detection of the agglutination of many types of particles, including latex, silica microparticles, and biological cells. UPA is easily adapted to detect any target molecules for which antibodies can be raised. Comparison tests of UPA to conventional particle agglutination assays have demonstrated a 20 fold increase in sensitivity for hemagglutination assays and a 30- to 1000-fold increase in the sensitivity of detection of HIV antibodies and food-borne pathogenic bacteria such as E.coli and Listeria monocytogenesis, respectively. In particular, with respect to HIV testing, we have determined that UPA is approximately 20-fold more sensitive than immunochromatography tests for detection of HIV antibodies.

The UPA immunoassay is a sensitive and rapid method that utilizes inexpensive instrumentation. The volume of sample needed for the test can be less than 10 microliters and testing takes only minutes. The UPA immunoassay consists of mixing a sample with sensitized latex particles or red blood cells, and placing the mixture into the ultrasonic resonator cell of the UPA device. In the UPA device, the mixture is subjected to ultrasonic exposure, and the formation of aggregates is detected. The quantitative results are displayed on an LCD display.

Unlike conventional agglutination assays, UPA is a simple one-step assay. The only action that needs to be performed by the operator is to load the reagent mixture into the device. The quantitative test result can be seen on the device display or computer screen in approximately 1-3 minutes from the start of the reaction. Thus, the subjective evaluation of the test results is eliminated, sensitivity is improved, and testing times are shortened compared to conventional assays.