Cyclin E belongs to the highly conserved cyclin family, whose members exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. Cyclins function as regulators of CDK kinases. Cyclin E forms a complex with and functions as a regulatory subunit of CDK2, whose activity is required for cell cycle G1/S transition. Cyclin E accumulates at the G1-S phase boundary and is degraded as cells progress through S phase. Cyclin E overexpression has been observed in many tumors, which results in chromosome instability, and thus may contribute to tumorigenesis. Primary antibodies are available purified, or with a selection of fluorescent CF® Dyes and other labels. CF® Dyes offer exceptional brightness and photostability. Note: Conjugates of blue fluorescent dyes like CF®405S and CF®405M are not recommended for detecting low abundance targets, because blue dyes have lower fluorescence and can give higher non-specific background than other dye colors.