Device for performing a diagnostic test and methods for use thereof
Assay cassettes and testing devices that can be used to provide rapid, accurate, affordable, laboratory-quality testing at the point of care. Such assay cassettes and testing devices are designed to provide rapid, quantitative test results in a point-of-care setting or the like. Likewise, such assay cassettes and testing devices may eliminate or replace expensive, centralized clinical testing equipment and technical personnel. Such testing device may include automated data reporting and decision support. Methods for performing point of care diagnostic tests are also disclosed.
1. A method for detecting at least one analyte of interest in a sample, the method comprising:
providing a lateral-flow chromatographic assay cassette that includes: a capture ligand, at least one reporter substance for visualizing the interaction of the analyte of interest and the capture ligand, and means for providing an at least a two-point calibration curve for quantification of the at least one analyte of interest;
providing a handheld computing device selected from the group consisting of a handheld digital camera device, a cellular phone, a smart phone, and a table computer;
providing a testing apparatus configured to be coupled to the handheld computing device and configured to position the lateral-flow chromatographic assay cassette in proximity to a detector and a light source to control focal length from the detector to the lateral-flow chromatographic assay cassette and to control illumination of the lateral-flow chromatographic assay cassette by the light source, wherein the testing apparatus comprises an assay cover including a manual or electromechanical device configured to allow the angle of the lateral flow assay cassette to be adjusted relative to the light source to sample a number of angles while the handheld computing device collects data to determine the optimum angle for detection;
the light source being capable of transmitting at least one wavelength of light configured to yield a detectable signal from the at least one reporter; and
a detector is positioned to capture the detectable signal from the at least one reporter;
applying a liquid sample to the lateral-flow chromatographic assay cassette, wherein the sample includes at least one analyte of interest;
inserting the lateral-flow chromatographic assay cassette into the testing apparatus;
illuminating the lateral-flow chromatographic assay cassette to yield a detectable signal from the at least one reporter substance; and
querying an interpretive algorithm stored in a computer readable format and electronically coupled to the handheld device, wherein the interpretive algorithm is configured for (i) calculating a calibration curve and the (ii) converting the detectable signal from the at least one reporter to a numerical value related to the presence or amount of the at least one analyte present in a sample.
2. The method of claim 1 , wherein the capture ligand includes at least one of an antibody, an epitope, or a nucleic acid immobilized on the lateral-flow chromatographic assay cassette.
3. The method of claim 1 , further comprising mixing the liquid sample with a dye conjugate prior to applying the sample to the lateral-flow chromatographic assay cassette, wherein the dye conjugate is configured to interact with at least one of the analyte of interest or the capture ligand to provide a visual readout related to the presence or concentration of the analyte of interest in the sample.
4. The method of claim 1 , wherein the detectable signal includes at least one of emission, color intensity, reflectance, diffuse scattering, elastic light scattering, transmission, fluorescence, surface plasmon detection, Rayleigh scattering, electrochemical detection, conductivity, or absorbance.