1 Usually, staph bacteria donât cause any harm. 2  However,if they get inside the body they can cause an infection. 3  When common antibiotics donât kill the staph bacteria, it means the bacteria have become resistant to those antibiotics. 4  This type of staph is called MRSA (Methicillin-Resistant Staphylococcus aureus).
A genetic marker is defined as a specific gene or DNA sequence that produces a detectable trait with a known location on a chromosome and that can be used to study family and population, identification of cells, species or individual. Introduction:
Carcinoembryonic antigen (CEA) is a tumor marker that is measured using a blood test. High levels of CEA may indicate that cancer has spread; however, other medical conditions and some treatments, including certain types of chemotherapy, may raise CEA levels. tumor marker is a substance found in a person's blood, urine, or the tumor itself. It is produced by the tumor or the body in response to cancer, or a noncancerous condition, such as inflammation. Your doctor may suggest tumor marker tests at various stages in the diagnosis and treatment of cancer.