​Spermatozoa Sorting Techniques for the Sex Pre-selection: A Review

Furtherance of sex pre-selection techniques is extremely beneficial for the farm productivity and economic growth of the country. Several techniques such as flow cytometry, swim-up, percoll gradient centrifugation, lumisort and immunogenic spermatozoa sexing developed so far are reviewed with their principles, advantages, disadvantages and possible ways for developing a highly reliable and efficient technique to achieve success in obtaining offspring of the desired sex. Out of all these techniques available till now, sorting X- and Y- spermatozoa using fluorescence-activated cell sorter (FACS) is the most successful and commercially available technique, which employs sorting of spermatozoa based on DNA content. Despite its effectiveness, there are disadvantages concerning cost, sperm damage, trained technical person, low conception rate, etc. An alternative approach that might have potential significance could be the identification of sex-specific membrane marker proteins for the immunological method of spermatozoa sorting.

Microfluidics sorting enables the isolation of an intact cellular pair complex of CD8+ T cells and antigen-presenting cells in a cognate antigen recognition-dependent manner

Adaptive immune responses begin with cognate antigen presentation-dependent specific interaction between T cells and antigen-presenting cells. However, there have been limited reports on the isolation and analysis of these cellular complexes of T cell-antigen-presenting cell (T/APC). In this study, we successfully isolated intact antigen-specific cellular complexes of CD8+ T/APC by utilizing a microfluidics cell sorter. Using ovalbumin (OVA) model antigen and OT-I-derived OVA-specific CD8+ T cells, we analyzed the formation of antigen-specific and antigen-non-specific T/APC cellular complexes and revealed that the antigen-specific T/APC cellular complex was highly stable than the non-specific one, and that the intact antigen-specific T/APC complex can be retrieved as well as enriched using a microfluidics sorter, but not a conventional cell sorter. The single T/APC cellular complex obtained can be further analyzed for the sequences of T cell receptor Vα and Vβ genes as well as cognate antigen information simultaneously. These results suggested that this approach can be applied for other antigen and CD8+ T cells of mice and possibly those of humans. We believe that this microfluidics sorting method of the T/APC complex will provide useful information for future T cell immunology research.

Extremely High-Throughput Parallel Microfluidic Vortex-Actuated Cell Sorting

We demonstrate extremely high-throughput microfluidic cell sorting by making a parallel version of the vortex-actuated cell sorter (VACS). The set-up includes a parallel microfluidic sorter chip and parallel cytometry instrumentation: optics, electronics and control software. The result is capable of sorting lymphocyte-sized particles at 16 times the rate of our single-stream VACS devices, and approximately 10 times the rate of commercial cell sorters for an equivalent procedure. We believe this opens the potential to scale cell sorting for applications requiring the processing of much greater cell numbers than currently possible with conventional cell sorting.