Measurement of RBC agglutination with microscopic cell image analysis in a microchannel chip.

Since Landsteiner's discovery of ABO blood groups, RBC agglutination has been one of the most important immunohematologic techniques for ABO and RhD blood groupings. The conventional RBC agglutination grading system for RhD blood typings relies on macroscopic reading, followed by the assignment of a grade ranging from (-) to (4+) to the degree of red blood cells clumping. However, with the new scoring method introduced in this report, microscopically captured cell images of agglutinated RBCs, placed in a microchannel chip, are used for analysis. Indeed, the cell images' pixel number first allows the differentiation of agglutinated and non-agglutinated red blood cells. Finally, the ratio of agglutinated RBCs per total RBC counts (CRAT) from 90 captured images is then calculated. During the trial, it was observed that the agglutinated group's CRAT was significantly higher (3.77-0.003) than that of the normal control (0). Based on these facts, it was established that the microchannel method was more suitable for the discrimination between agglutinated RBCs and non-agglutinated RhD negative, and thus more reliable for the grading of RBCs agglutination than the conventional method.

Comparison of the automated fluorescence microscopic viability test with the conventional and flow cytometry methods.

The cell viability test is an essential tool in any laboratory, performing cell-based studies and clinical laboratory tests. The trypan blue exclusion method is the most popular assay for its simple concept among various diagnostic tools. However, several disadvantages include time-consuming and labor-intensive steps with low precision. In this study, we evaluated a new technique for the automatic cell viability measurement with microscopic cell counter and microchip. Upon blood draw from 11 healthy volunteers, Mononuclear cells were separated immediately from the heparinized whole blood, and the viable cells were diluted from 100 to 1%. The cell viability tests were performed simultaneously with following three methods: the conventional manual trypan blue exclusion method; the flow cytometry measurement with propidium iodide stain; and the newly developed microscopic cell counter with microchip. Linearities, precisions, and correlations from three methods were analyzed and compared. The correlations data from the microscopic cell counter were in good agreement with both the conventional trypan blue method (r=0.99, P<0.05) and the flow cytometry (r=0.99, P<0.05), respectively. The precision (2.0-6.2%) and linearity from the microscopic cell counter method with microchip were superior in comparison with the conventional method. The microscopic cell counter with microchip performed well with high precision, linearity, and efficient running time than both the manual trypan blue and the flow cytometry methods.

Absolute CD4+ cell count using a plastic microchip and a microscopic cell counter.

We have designed and evaluated the performance of a simple, rapid, and affordable method for counting CD4(+) T-cells with the use of plastic microchips. This new system is an adaptation of a "no-lyse, no-wash," volumetric single platform assay, and absolute CD4(+) counts are determined with the use of a microscopic scanning cell counter. To assess the CD4(+) count test precision and linearity of the system, measured CD4(+) counts were compared with two other reference assays (single and dual platform flow cytometry) with the use of 123 clinical samples including samples obtained from 35 HIV-infected patients, and artificially diluted samples. A correlation between the results from the use of the new method and from the use of the two other reference assays was r = 0.98 for the clinical samples. A dilution test of the new method demonstrated a linearity of r >or= 0.99, with coefficients of variation