Bromodeoxyuridine Labeling of S-Phase Nuclei in the Starlet Sea Anemone Nematostella vectensis

INTRODUCTION

Bromodeoxyuridine (BrdU) is a thymidine analog that can be used to label cells in the S-phase of the cell cycle. BrdU penetrates the cell membrane and is rapidly integrated into the nucleotide pool, ready to be incorporated into DNA. A specific antibody against BrdU coupled to a fluorophore or an enzyme (alkaline phosphatase [AP] or horseradish peroxidase [HRP]) can detect BrdU incorporated into DNA. The method is simple and powerful, because the combination of pulse, continuous, and pulse-chase labeling allows deep insights into the cell-cycle dynamics and differentiation kinetics of a number of cycling and terminally differentiated cells. This protocol describes BrdU labeling of S-phase nuclei in the starlet sea anemone Nematostella vectensis.