To use all functions of this page, please activate cookies in your browser.
With an accout for my.bionity.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
- My watch list
- My saved searches
- My saved topics
- My newsletter
A marker gene is used in molecular biology to determine if a piece of DNA has been successfully inserted into the host organism. There are two types of marker genes: selectable markers and markers for screening.
Additional recommended knowledge
A selectable marker will protect the organism from a selective agent that would normally kill it or prevent its growth. In most applications, only one in a several million or billion cells will take up DNA. Rather than checking every single cell, scientists use a selective agent to kill all cells that do not contain the foreign DNA, leaving only the desired ones.
Antibiotics are the most common selective agents. In bacteria, antibiotics are used almost exclusively. In plants, antibiotics that kill the chloroplast are often used as well, although tolerance to salts and growth-inhibiting hormones is becoming more popular. In mammals, resistance to antibiotics that would kill the mitochondria is used as a selectable marker.
A marker for screening will make cells containing the gene look different. There are three types of screening commonly used:
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Marker_gene". A list of authors is available in Wikipedia.|