Lab work is work done inside of the Crime Labs. Lab work is done by both lab techs and Crime Scene Investigators. All lab techs and CSIs wear various lab coats in the lab. In Las Vegas, the lab coats were originally light blue before changing to dark blue. Each Vegas lab tech and CSI wears a lab coat with "Forensics" on the label as well as an ID card identifying the person. In Miami, at first, the lab coats were also light blue with an ID card as well. In later seasons, the colour remained the same but the names and surnames were added as well, eg, Speedle's lab coat was T. Speedle.