Molecular cytometry

The first flow cytometric analyses were of total cellular DNA or protein content. The advent of labeled antibodies, first polyclonal and then monoclonal, led to the analysis of cellular content of specific antigen molecules and a myriad of immunological applications. Although, strictly speaking, it is incorrect to use the word "cytometry" for anything that does not refer to cellular measurements, the term has been used for a variety of non-cellular measurements such as chromosome analysis and solution molecular measurements. In recent years, there has been an increase in the development of methods to analyze molecules and their properties in solution. These analyses have ranged from ensemble measurements, primarily fluorescence-based immunoassays, to single molecule detection with applications in DNA analysis.