In order to better understand cellular processes and behavior, a controlled way of studying high numbers of single cells and their clone formation is greatly needed. This chapter describes a microwell plate with 672 wells in a standard array/slide format, applied for single-cell culture and analysis. Single cells can be seeded into each well of the plate (1) manually or (2) automatically using a sorting flow cytometer, followed by week-long culture and detection of cell growth, protein expression, etc. The glass/silicon plate is compatible with most standard instrumentation to facilitate easy handling and enable use of the plate for single-cell analysis in most laboratory settings.