The present invention relates generally to recombinant genetic technology. More particularly, the present invention relates to compositions and methods for use in selection and isolation of nucleic acid molecules. The invention further relates to methods for the preparation of individual nucleic acid molecules and populations of nucleic acid molecules, as well as nucleic acid molecules produced by these methods. The invention also relates to screening and/or selection methods for identifying and/or isolating nucleic acid molecules which have one or more common features (e.g., characteristics, activities, etc) and populations of nucleic acid molecules which share one or more features.