Green fluorescent protein

A method for selecting cells expressing a protein of interest which comprises:

• a) introducing into the cells a first DNA molecule having a DNA sequence encoding the protein of interest and a second DNA molecule having a DNA sequence encoding a fluorescent mutant of green fluorescent protein of Aeguorea victoria;
• b) culturing cells resulting from step (a) under conditions permitting expression of the fluorescent mutant of green fluorescent protein and the protein of interest;
• and
• c) selecting the cultured cells which express the fluorescent mutant of green fluorescent protein, thereby selecting cells expressing the protein of interest.

A method for localizing a protein of interest in a cell which comprises:

• a) introducing into a cell a DNA molecule having a sequence encoding the protein of interest linked to a DNA sequence encoding a fluorescent mutant of green fluorescent protein of Aequorea victoria such that the protein produced by the DNA molecule will have the protein of interest fused to the fluorescent mutant of green fluorescent protein of Aequorea victoria;
• b) culturing the cell under conditions permitting expression of the fused protein;
• and
• c) detecting the location of the fused protein, thereby localizing the protein of interest in the cell.

A method of detecting expression of a gene in a cell which comprises:

• a) introducing into the cell a DNA molecule having the sequence of the gene linked to a DNA molecule encoding a fluorescent mutant of green fluorescent protein of Aequorea victoria such that a regulatory element of the gene controls expression of the fluorescent mutant of green fluorescent protein of Aequorea victoria;
• b) culturing the cell under conditions permitting expression of the gene;
• and
• c) detecting the expression of the fluorescent mutant of green fluorescent protein of Aequorea victoria in the cell, thereby detecting expression of the gene in the cell.

A method for detecting expression of a gene in a living organism which comprises:

• a) introducing into a cell of the subject a DNA molecule having the sequence of the gene linked to a DNA molecule encoding a fluorescent mutant of green fluorescent protein of Aequorea victoria such that a regulatory element of the gene controls expression of the fluorescent mutant of green fluorescent protein of Aequorea victoria;
• b) culturing the cell under conditions permitting expression of the gene;
• and
• c) detecting the expression of the fluorescent mutant of green fluorescent protein of Aequorea victoria in the cell, thereby detecting expression of the gene in the living organism.

A method for producing a fluorescent molecular weight protein marker comprising:

• a) linking a first DNA molecule encoding a fluorescent mutant of green fluorescent protein of Aequorea victoria with a second DNA molecule encoding a known amino acid sequence which is in the same reading frame as the first DNA molecule;
• b) introducing the linked DNA molecule of step (a) into a protein expression system permitting the expression of a fusion protein comprising the fluorescent mutant linked to the known amino acid sequence;
• c) recovering the fusion protein expressed in step (b):
• and
• d) determining the molecular weight of the fusion protein from step (c), thereby producing a fluorescent molecular weight protein marker.