When referring to the genotype (the gene) the mnemonic is italicized and not capitalised. When referring to the gene product or phenotype, the mnemonic is first-letter capitalised and not italicized (e.g. DnaA – the protein produced by the dnaA gene; LeuA – the phenotype of a leuA mutant; Amp – the ampicillin-resistance phenotype of the β-lactamase gene bla).