We have recently developed a 2D light scattering static cytometer for cellular analysis in a label-free manner, which measures side scatter (SSC) light in the polar angular range from 79 to 101 degrees. Compared with conventional flow cytometry, our cytometric technique requires no fluorescent labeling of the cells, and static cytometry measurements can be performed without flow control. In this paper we present an improved label-free static cytometer that can obtain 2D light scattering patterns in a wider angular range. By illuminating the static microspheres on chip with a scanning optical fiber, wide-angle 2D light scattering patterns of single standard microspheres with a mean diameter of 3.87 μm are obtained. The 2D patterns of 3.87 μm microspheres contain both large-angle forward scatter (FSC) and SSC light in the polar angular range from 40 to 100 degrees, approximately. Experimental 2D patterns of 3.87 μm microspheres are in good agreement with Mie theory simulated ones. The wide-angle light scattering measurements may provide a better resolution for particle analysis as compared with the SSC measurements. Two dimensional light scattering patterns of HL-60 human acute leukemia cells are obtained by using our static cytometer. Compared with SSC 2D light scattering patterns, wide-angle 2D patterns contain richer information of the HL-60 cells. The obtaining of 2D light scattering patterns in a wide angular range could help to enhance the capabilities of our label-free static cytometry for cell analysis.
Cytometry has wide applications in biomedicine for cell differentiation or disease monitoring. Here we report our newly developed two dimensional (2D) light scattering static cytometric technique for single and multiple cell analysis. The static cytometer adopts a scanning fiber probe for cell excitation and obtains 2D light scattering patterns on a complementary metal oxide semiconductor (CMOS) detector. Our results show that experimental 2D light scattering patterns obtained from single yeast cells are with fringe structure while those from multiple yeast cells give speckle patterns. The experimental results compare favorably with our 2D light scattering Mie theory simulations for both single and multiple cells. The varying of 2D light scattering patterns with different yeast cell clusters, either number or distribution changes, shows the potential of our 2D light scattering static cytometer for cellular diagnostics.