Novel jet-in-air fluidic systems for cell to embryo analysis and sorting

Flow cytometry, a fluorescent activated cell-sorting technology coupling the physical sciences with the biological and medical sciences, has truly revolutionised the analysis of cellular populations at a single cell resolution. Here, the coupling of advanced hydrodynamics, laser technology, molecular biology and computer acquisition, to name a few, working in concert, has generated a technology unrivalled to date, in its category, namely, the ability to analyse critical characteristics of single cells in populations to their purification for a given characteristic. A wide range of living biological units have been analysed, exploring current flow cytometry, ranging from cells to sperm. Although these living biological units have been successfully analysed through a variety of their characteristics, the technology is somewhat hindered by the needles explored for their introduction to the interrogation point. Current flow cytometry and sorters use needles having diameters in the range of approximately 50–200 μm [1]. Unfortunately, such needles have been reported to cause cell damage/death in analysed cells through induced stresses during the analysis of fragile and/or larger cell types, etc., which is commonly referred to as sorter induced cell stresses (SICS). In this discussion article, the author introduces two alternative jet-in-air technologies, exploring needles with inner bore diameters > > 1000 µm, which eliminate stresses experienced by cells during their flow within them. These two alternative jet-in-air approaches work on either pressure- or electric-field gradients and are widely referred to as aerodynamically assisted bio-jets and bio-electrosprays, respectively. Interestingly, they possess the capacity to handle cell volumes > 5 × 10 6 cells/ml to the handling of oocytes and whole fertilised embryos.