Organism names in italics

There is really no excuse for writing this incorrectly. It makes you look sloppy and it makes you look like a bad scientist.

Organism names (in their binomial nomenclature) should be written in italics. The genus should be capitalised (e.g. Drosophila) but the species should not be capitalised (e.g. melanogaster). 

Give the full name (e.g. Escherichia coli) once. After that, the abbreviation (e.g. E. coli) should be used throughout the entire text.

Do not use an abbreviation without defining it beforehand.

For example:

Escherichia coli K-12 carrying the engineered plasmid was cultivated in Lysogeny broth (LB) with 25 mg/L neomycin at 37°C. Colony morphology investigation of E. coli was carried on on LB agar.

Possible exceptions:

Many style guides say that the first word of a new sentence should not be an organism abbreviation. Re-write the sentence so the organism does not appear at the start of the sentence, or write out the Genus name.