Cells are the fundamental units of biology,the current experimental approaches are mostly based on studying bulk cell population rather than single cell,which would unavoidably lead to an average result and possibly disguise cellular heterogeneity of functional significance.In fact,cellular heterogeneity is a general feature of biological systems and some theoretical and practical problems can be solved only at single-cell level.But it is difficult to analyze gene expression at single-cell level single cell.Digital PCR has proved to be a highly sensitive nucleic acid quantification technique which can detect single molecule individually.The sample is diluted and partitioned into hundreds of separate reaction chambers so that each chamber contains only one or no copies of the target DNA.The copies of a sample can be determined by counting the number of positive partitions versus negative partitions after endpoint PCR.A self-priming compartmentalization(SPC)microfluidic digital PCR chip was designed which is capable of performing single molecule amplification of genes from single cell.With the SPC digital PCR chip,the gene copy number of single cell can be absolute quantify with higher sensitivity,reduced labor time and reagent.