Human blood is typed according to whether certain markers, called antigens, are present on the surface of red blood cells.

More than 15,000 markers, called sequence tagged sites, have been located on the map.

Each course has several checkpoints denoted by markers called "controls."

When a marker called inhibin-A is added to the screen, it is known as the quad marker.

In 2009, Japanese researchers identified a urinary marker called phenylacetylglutamine that could be used for early diagnosis.

Also, people bearing the same genetic marker, called M3, live on either side of the former bridge, suggesting it was the means of passage.

Sometimes rough-cast leaden markers called dumps were used.

To mark cards faster the players usually use special markers called daubers.

There is a more common marker called inverted duplication of chromosome 15.

If you are Rh-negative, your red blood cells do not have a marker called Rh factor on them.