Typical marker genes are for antibiotic resistance or nutrient biosynthesis.

The marker genes tell the researchers "which lymphcytes are actually working to stop the cancer," allowing them to more accurately target their effort.

Some concern has been raised about the safety of "marker" genes.

F9 cell differentiation is characterised by the induction of different marker genes.

Many of these plants are engineered with the aid of antibiotic-resistant "marker" genes.

Two others have just the marker gene, Dr. Campbell said.

In the first trial the cells will be given a marker gene to allow them to be traced in the body.

The directive should take a clear stand and insist that the use of these marker genes is stopped now.

We have achieved the phasing out of all harmful, antibiotic-resistant marker genes.

The disputed antibiotic-resistant marker genes will be banned in Europe in the future.