Sized-based marker identification technology

A method for producing a plurality of labeled cells which can be individually identified, comprising the step of:

• introducing into a plurality of separate cells an exogenous DNA fragment which differs in length in each said separate cell, and which stably insert into a chromosome of each said separate cell.

A set of labeled cells wherein a chromosome of each cell of said set contains an exogenous DNA fragment which differs in length between each member of said set.

A method for monitoring the distribution or fate of a cell in a growth environment comprising the steps of:

• forming a labeled cell with an exogenous DNA fragment of a defined length stably integrated into the chromosome of said cell,
• introducing said labeled cell into said growth environment for a period of time sufficient for growth of said cell and determining the distribution or fate of said cell by the presence of said exogenous DNA fragment.

A method for identifying a strain of viruses containing a mutation in a gene involved in growth in a cell, comprising the steps of:

• a) forming a labeled set of strains comprising a plurality of members, each member of said set containing an exogenous DNA fragment of a defined length stably integrated into the chromosome of said member, said defined length in each said member differing from said defined length in other said members,
• b) subjecting said labeled set of strains to mutagenesis so as to obtain mutants from each member of said set of strains, and
• c) introducing viruses of said mutant strains into a growth environment for a period of time sufficient for growth of a non-mutated strain and determining which strains have altered growth compared to a non-mutated strain, by determining the presence and size of said exogenous DNA fragments relative to each other.

A method for producing a plurality of labeled viruses which can be individually identified, comprising the step of:

• introducing into a plurality of separate viruses an exogenous DNA fragment which differs in length in each said separate virus, and is able to stably insert into a chromosome of each said separate virus.

A set of labeled viruses wherein a chromosome of each virus of said set contains an exogenous DNA fragment which differs in length between each member of said set.