High-Throughput Whole-Plate Imaging of Cells for Multiple Biological Applications

Advanced multipurpose cell imaging systems along with integrated rapid quantitation software can enhance and expedite cancer cell culture studies in a variety of applications. Though accurate cell culture studies are an important and necessary component of nearly all cancer biomarker detection and therapy studies, the methods we currently use are of low-throughput, time consuming, and lack accuracy. Hence, it is important to improve several features of the assays to increase the accuracy of their quantitative outputs in most studies. In general, we perform cell culture analysis semimanually by counting a small aliquot of suspended cells using a hemocytometer or viewing a small area of cells on a plate using a bright-field microscope, and then extrapolate the counts or observations to estimate the values for the total numbers of cells. The fundamental problem with this process lies in using techniques, such as extrapolation, which inherently introduces intrasample variability while collecting the cells by enzymatic trypsinization for these assays that are affecting cell growth and other downstream assessments. Fluorescence (FL) microscopy-based assays are also used to image and count cells for various applications, including cell viability, proliferation, apoptosis, cell death, transfection efficiency, protein expression, stem cell properties, colony formation, cytotoxicity, drug dose-response, and treatment efficacy studies. These methods are not optimal for many researches, as they require real-time visualization under a microscope plus manual analysis to determine the final results. Owing to long exposure times for cells under fluorescent light of a microscope, the cells may be exposed to suboptimal conditions that affect cell growth, and with occasional photobleaching of the expressed FL probes. Alternatively, the use of cell imaging systems that integrate both advanced bright-field and FL imaging for cell counting and quantification can be useful. In this protocol, we discuss the advantages of a high-throughput cell imaging system using a whole-plate imaging format when used in various bioimaging studies by highlighting a few applications of the system. The system is designed to fundamentally improve the accuracy and time of cell culture analysis while also allowing us to perform the assay without trypsinization, thus avoiding the need to replicate multiple wells for monitoring cell growth over time.