Diagnostic test for Fragile X, using presence (normal) or absence (Fragile X syndrome) of FMR-1 protein. FMR-1 protein expression in blood cells has been made visible with antibodies against the FMR-1 protein. The presence of FMR-1 protein is made visible as red staining. a: red staining in cells of normal individual. b/c: absence of staining in male patient. d: female patient; one cell is showing staining and in the other cell there is an absence of staining - this individual is a carrier.