Using Intravital Dyes to Ubiquitously Label Embryonic Zebrafish

INTRODUCTION

In the last two decades, the small tropical freshwater-dwelling zebrafish has emerged as a popular model for developmental biologists. The exceptional optical accessibility of zebrafish embryos coupled with the ability to use genetic tools to indelibly tag cells have been exploited to watch developmental events as they unfold. Moreover, because zebrafish are vertebrates, the knowledge gained through such studies is broadly applicable. This protocol describes the use of intravital dyes to ubiquitously label embryonic zebrafish. Intravital dyes such as CellTrace BODIPY TR methyl ester can be used to counterstain embryos that express fluorescent proteins either through transient injections or by stable transgenics. BODIPY TR should only be used in combination with fluorescent proteins that can be spectrally separated from it. The BODIPY TR absorption spectrum peaks at 598 nm, and its emission spectrum peaks at 625 nm. Embryos should be stained just before imaging.