4π light scattering flow cytometry: enhancing the identification and characterization of individual cells.

The analysis of individual particles with complex morphologies from light scattering is crucial in disperse systems studies, such as blood cells. Characterization, which assumes determining particle characteristics, has a higher likelihood of succeeding in solving the inverse light-scattering problem if an instrument provides enough light-scattering data. In this study, we demonstrate how we extend the operating angular interval for the 4π Scanning Flow Cytometer (4πSFC), which measures angle-resolved light-scattering profiles (LSPs) of individual particles.

Ultraviolet light scattering scanning flow cytometry in the characterization of submicron microparticles.

Ultraviolet lasers are commonly used in flow cytometry to excite fluorochrome molecules with subsequent measurement of the specific fluorescence of individual cells. In this study, the performance of the ultraviolet light scattering (UVLS) in the analysis of individual particles with flow cytometry has been demonstrated for the first time. The main advantage of the UVLS relates to the improvement of the analysis of submicron particles due to the strong dependence of the scattering efficiency on the wavelength of the incident light.

A light scatter based model relating erythrocyte vesiculation to lifetime in circulation.

Methods for measuring erythrocyte age distribution are not available as a simple analytical tool. Most of them utilize the fluorescence or radioactive isotopes labeling to construct the age distribution and support physicians with aging indices of donor's erythrocytes. The age distribution of erythrocyte may be a useful snapshot of patient state over 120-days period of life.

Erythrocyte lysis and angle-resolved light scattering measured by scanning flow cytometry result to 48 indices quantifying a gas exchange function of the human organism.

Molecular/cell level of gas exchange function assumes the accurate measurement of erythrocyte characteristics and rate constants concerning to molecules involved into the CO /O transport. Unfortunately, common hematology analyzers provide the measurement of eight indices of erythrocytes only and say little about erythrocyte morphology and nothing about rate constants of cellular function. The aim of this study is to demonstrate the ability of the Scanning Flow Cytometer (SFC) in the complete morphological analysis of mature erythrocytes and characterization of erythrocyte function via measurement of lysing kinetics.

Advanced consumable-free morphological analysis of intact red blood cells by a compact scanning flow cytometer.

Whereas modern automated blood cell analyzers measure the volume of individual red blood cells (RBCs), leading to four RBC indices (mean corpuscular volume, MCV; mean corpuscular hemoglobin, MCH; mean corpuscular hemoglobin concentration, MCHC; red cell distribution width, and RDW), the RBC shape has not been assessed by clinical screening tools. We applied the scanning flow cytometer (SFC) for complete characterization of intact RBC morphology in terms of diameter, maximal and minimal thicknesses, volume, surface area, sphericity index, spontaneous curvature, hemoglobin concentration, and content. The above-mentioned individual RBC characteristics were measured without fluorescent markers and other chemicals by a SFC equipped only with 660 nm laser for RBC illumination and single detector for measurement of angle-resolved light scattering.

Mature red blood cells: from optical model to inverse light-scattering problem.

We propose a method for characterization of mature red blood cells (RBCs) morphology, based on measurement of light-scattering patterns (LSPs) of individual RBCs with the scanning flow cytometer and on solution of the inverse light-scattering (ILS) problem for each LSP. We considered a RBC shape model, corresponding to the minimal bending energy of the membrane with isotropic elasticity, and constructed an analytical approximation, which allows rapid simulation of the shape, given the diameter and minimal and maximal thicknesses. The ILS problem was solved by the nearest-neighbor interpolation using a preliminary calculated database of 250,000 theoretical LSPs.

Comparison of the discrete dipole approximation and the discrete source method for simulation of light scattering by red blood cells.

The discrete sources method (DSM) and the discrete dipole approximation (DDA) were compared for simulation of light scattering by a red blood cell (RBC) model. We considered RBCs with diameters up to 8 mum (size parameter up to 38), relative refractive indices 1.03 and 1.

Is there a difference between T- and B-lymphocyte morphology?

We characterize T- and B-lymphocytes from several donors, determining cell diameter, ratio of nucleus to cell diameter, and refractive index of the nucleus and cytoplasm for each individual cell. We measure light-scattering profiles with a scanning flow cytometer and invert the signals using a coated sphere as an optical model of the cell and by relying on a global optimization technique. The main difference in morphology of T- and B-lymphocytes is found to be the larger mean diameters of the latter.