Description
Methyl Paraben (Nipagin) Powder – Preservative for Drosophila Culture Media
For preparation of fruit-fly culture media only. Not for direct use on amphibians, reptiles or other vertebrates.
Methyl paraben (methyl 4-hydroxybenzoate, often called Nipagin or Tegosept in fly-culture literature) is widely used as a preservative in laboratory Drosophila diets, particularly to suppress fungal growth.
Important correction
We previously described methyl paraben as preventing both mould and bacterial contamination and gave a blanket dose of 3–5 g per litre of dry medium. We have removed those statements. Published fly-media recipes vary considerably in preservative concentration and preparation method, and methyl paraben itself can influence fly biology and microbial interactions.
Use a validated fruit-fly media recipe rather than adding an arbitrary amount. Research and stock-centre recipes commonly prepare methyl paraben as a solution before it is incorporated into cooled media. The final concentration depends on the complete recipe.
Handling
- Follow the safety information supplied with the chemical.
- Avoid breathing powder or getting it in the eyes.
- Use suitable gloves and good hygiene during preparation.
- Keep away from children, animals and food-preparation areas.
- Do not dust feeder insects with methyl paraben and do not expose frogs directly to the powder or concentrate.
Culture note
Preservatives reduce some contamination problems; they do not make cultures sterile or eliminate every fungus or bacterium. Good culture hygiene, clean containers, suitable media moisture and routine replacement remain important.
Culture-Media Evidence Review
Last reviewed: 5 September 2026
Methyl paraben is an established ingredient in many laboratory Drosophila diets, but its concentration and biological effects depend on the formulation. Frogfather therefore no longer gives one universal dose for all home culture media.
Evidence & further reading
- Protocols for ageing studies in Drosophila – Tegosept-containing diets
- A holidic medium for Drosophila melanogaster – preservative formulation
- Henry et al. – methyl paraben can alter bacterial infection outcomes in Drosophila
