VALIDATION OF HIGH-SENSITIVITY FLOW CYTOMETRIC ASSAYS

Sensitivity validation of high-sensitivity flow cytometric assays encompasses determining three different specifications: the analytical sensitivity: limit of blank (LOB) and limit of detection (LOD) and the functional sensitivity: LLOQ. The LOB is the highest signal expected in absence of the measurand, or the assay background. The LOD is the lowest signal above background which can be detected. The LLOQ is the lowest signal which can be precisely and accurately measured.

When establishing LOB/LOD and LLOQ it is important to note that they do not necessarily need to be established for each and every population reported in the panel. Establishing LOB/LOD and LLOQ is only required if the population of interest is expected to be low in the intended use samples. For example, in an assay in which circulating T follicular helper (Tfh) cells, phenotypically defined as CD3+CD4+CXCR5+ICOS+PD1+, the LOB/LOD and LLOQ of this rare population must be established.

Reference: https://doi.org/10.1002/cyto.b.21949