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.
In Season 2 or Season 3, the lab coats changed from blue to white yet still kept the name tags which have remained to this day as well as the ID card which is worn underneath the coat, usually on the belt.
In New York, lab tech personnel and CSIs wear white lab coats that have the words, "N.Y Crime Lab" on them.
- Several lab techs have moved from the lab to field work as a CSI. These include Greg Sanders in Las Vegas and Natalia Boa Vista in Miami. It should be noted that both Sanders and Boa Vista's speciality is DNA.
- Some lab techs leave the lab to do field work at a crime scene. For example, lab tech Adam Ross in New York specializes in Trace Evidence, and sometimes comes to crime scenes to aid in reconstruction or evidence collection and in Las Vegas, David Hodges and former lab tech Wendy Simms have both gone to various crime scenes to aid the CSIs.