A lab in particular can not have a serologist in its staff, its functions are performed by an expert criminologist, a biochemist, a forensic biologist, or another technician. These personnel usually have a bachelor's or master's degree, while a chief serologist possess a doctor or a Ph.D. is rare to find serologists boss, and the degree seems to be common. Some states have laws that make serology permissible by law, without the need for the testimony of an expert, whose purpose is to isolate and protect their crime lab technicians.
Other states rely on their chief coroner's office, forensic pathologists, toxicologists or certificate. Professor of biochemistry, hematology, immunology, and are often "borrowed" as experts by the prosecution and defense. In certain specialized areas to be studied blood stain (such as blood spatter analysis), the courts usually qualifies someone as an expert who has no formal education but specialized training and has made a sufficient number of tests and accumulated sufficient benchmarks to demonstrate the basis of their opinion.
Such experts are usually law enforcement, and his testimony is more common in those states that have amended or adopted Frye Coppolino. In addition, blood and bloodstains is an integral part of the crime scenes that a police detective / specialist in blood spots can be found in some jurisdictions, which shows in the final issue, despite that usurps the province of the jury. Federal Rule of Evidence 704 allows this to some degree. The impact of Daubert has led to a situation more in line with Federal Rule of Evidence 702 with a statistical validity and reliability. The probability estimates are often used in the testimony of the blood.