The Innovative Step: Ultra-Rapid Plasma Preparation Platform
FABPulous has developed a proprietary manual method of ultra-rapid plasma preparation that can make a defined dilution of plasma from a small volume (few drops) of whole blood in seconds. This makes possible a 5-minute blood test for assessment of specific plasma components that can be performed in the moment of need by non-technical staff at the point of care.
The device consists of a blood collector to absorb a small defined volume of blood from a finger prick, running buffer solution to dilute the blood, and a filtration stack to remove the solid cellular matter; this set-up allows for a pressure controlled filtration to produce diluted blood plasma (Fig. 1).
Figure 1. Plasma Separation Device
Plasma Separation Makes the Difference
By design, point-of-care (POC) platforms are used to rapidly deliver near-patient test results in order to support better patient management. Whole blood samples in traditional immunoassay platforms often result in slow or insensitive test performance compared with plasma/serum sample input. Removal of blood cells and accurate dilution of the prepared plasma is required to maintain test precision, requiring a moderate level of technical expertise. Platforms using microfluidics cannot handle whole blood samples due to their design. Consequently, the time to plasma preparation largely determines the overall time needed to produce a test result with many of the current POC tests. The FABPulous ultra-rapid plasma preparation device prepares diluted plasma in seconds and can significantly reduce time-to-result, which carries high medical value, especially under circumstances that require urgent medical decisions.
Integrated Lateral Flow IVD Platform
Based on this sample preparation device, the in vitro diagnostic (IVD) test platform consists of two parts, i.e., the same blood collection unit as described and a cartridge that contains a filter stack and a lateral flow immunoassay strip (Fig. 2).
Figure 2. IVD test platform: Consists of the blood collector and buffer compartment (blue-white part) and the cartridge which holds the filter stack and lateral flow strip.
The blood collector is docked onto the cartridge. Twisting the blue cap pushes the buffer contained in the device through the blood collection pad and the now diluted whole blood is passed under controlled pressure through the filter stack to produce accurately diluted plasma, which is guided to a lateral flow strip to produce a final result in 5 minutes (negative) or earlier if positive.
Added Value of the FABPulous Approach
Current state-of-the-art lateral flow assays on whole blood take 15-20 minutes at minimum to produce a test result and struggle to reach the necessary sensitivity, specificity, or both. The IVD test platform developed by FABPulous allows for a threefold reduction in the time-to-result, as it produces a test result in 2-5 minutes, coupled with higher precision. This rapid performance is of significant benefit in emergency situations where time is critical. In addition, it provides the general practitioner with a result within the time of a typical consultation, which is around 10 minutes.
Asked to describe their ideal POC test a General Practitioner will typically suggest “like a pregnancy test”. What they mean is simple enough to perform intuitively, without complicated, time-consuming and expensive instruments and providing a “Yes” / “No” result in less than 8 minutes. The True Rapid Test platform grants that wish. Its most important use will be in driving better diagnostic decisions in the out of hospital field of emergency medicine, helping to separate high and low risk patients with vague symptoms such as chest pain, breathlessness, feeling faint and headaches. Biomarkers such as H-FABP, cardiac Troponins, D-Dimer, BNP, βhCG and CRP are all obvious examples where a 5-minute finger prick blood test will help clinical decision making.
Integrated Assay Concept
Similarly, molecular diagnostic assays in whole blood samples for targets in plasma may benefit from the reduction of background nucleic acid from blood cells. Sample volume and dilution factors can be adjusted as needed for subsequent testing with any, if not all, technology platforms for plasma derived targets. It can be integrated with a subsequent detection platform or it can prepare intermediary samples for these.