Design On The Cellular Imaging And Recognition Based Portable Cell Counting Platform

Cell counting involves many key steps especially in biological detections and disease diagnostics.For example,a clear number of cells is helpful to determine the number of reagents and chemical materials used in experiments precisely,and to improve the accuracy of biological analysis,such as transfection,cell proliferation or viability research and quantitative polymerase chain reaction.Moreover,diseases such as anaemic can be diagnosed according to erythrocyte concentration by counting various blood cells.Therefore,it is of great significance to realize precise cell counting.It was originally developed for counting blood cells,and now it has become a tool for counting various types of cells,particles and small organisms.Although hemocytometer is simple and cheap,its counting results are unstable and its procedures are time-consuming and laborious.Flow cytometers can count and analyze cells rapidly and precisely.However,these systems are often complicated and expensive.Coulter counters can provide rapid cell counting often with low price,but it cannot distinguish live and dead cells,limiting their applications in cell viability detections.With the capability of cell recognition,counting and analysis,image processing based cell counters are widely used since details including cell concentration and viability can be extracted from the captured microscopic images.Additionally,high-throughput cell imaging systems combining with microscopy and microfluidics have also been provided extremely fast cell imaging and analysis ability.However,considering that most cell counters,flow cytometers and Coulter counters are still with large sizes and expensive costs;besides,hemocytometers still rely on complicated and expensive commercial microscopes,these cell counting devices are mostly used in laboratories limiting their applications in outdoors for field testing.Here,in order to realize on-site cell concentration and viability detection,we proposed a field-portable smartphone cell counter including the smartphone based bright-field microscope for cell imaging and the self-programed smart application for automatic cell recognition,counting and analysis.In this study,we designed a field-portable smart cell counter system composed of the smartphone based cell imaging and the self-programed smart application for automatic cell recognition,counting and analysis.In this system,light emitting diode(LED)is chosen for illumination,cell magnification optical microscopic system including 20× micro-objective,a reflecting mirror and an additional eyepiece,smartphone for image recording and data processing.The imaging resolution of this proposed system was tested using a USAF 1951 resolution test chart and the resolution reached 1.74 μm.Considering the average diameter of the trypsinized cells is around 10 μm,it is proved that the smart cell counter can provide high-quality cell imaging.Meanwhile,we designed a 3-D diagram of the proposed system composed of external and internal structure,then printed various components of the system using 3-D printing technology and assembled these components into a smartphone-based cell counter system with the compact size of 170 mm×113 mm ×168 mm.Moreover,this system is powered by two AA batteries without any extra external power supply,and according to the long battery life,the proposed smart cell counter can support continuous detections for 16 h.Additionally,a smart application is also designed for automatic cell concentration and viability detection by cell counting and live/dead cell distinguishing from directly captured bright-field images.Compared with the experimental results obtained by hemocytometer;commercial cell counter and flow cytometer,it is proved the smart cell counter can reach rather high accuracy in both cell concentration and viability detections.Besides,it is tested that the optimal cell concentration for the proposed smart cell counter is between 105 and 107 cells/mL.Moreover,the whole operations of the smartphone cell counter including multiple image recording and data processing of multiple fields of view(FoVs)can be finished rapidly only within minutes.The proposed smartphone cell counter in this study not only has the characteristics of low cost,small size and compact structure,but also has self-supplied power supply and supports long-time cell testing without any extra external power supply.Meanwhile,this system can realize cell counting and analysis in high precision and fast speed.Therefore,it especially suits for on-site cell concentration and viability detections.