Gram -ive

Escherichia coli is a Gram-negative straight rod, which either uses peritrichous flagella for mobility or is nonmotile. E coli is commonly found in the lower intestine of warm-blooded animals such as humans. The K12 strain has been modified so it can no longer survive in the human gut making it safe to work with.

Ideal for practical investigations into antibiotic efficacy.

E.coli K12 (NCTC 10538) is Lactose positive (Lac+), i.e. produces beta-galactosidease in the presence of lactase.

All Darwin's bacteria are derived from strains held by the British National Culture Collection (NCTC). These cultures are then sub-cultured before being applied to slopes and sold into schools and colleges across the UK. By sub-culturing we are able to supply quality bacteria at affordable prices. Our bacteria is a maximum of 4 passages away from the Culture Collection’s original. If you require fewer passages, or are purchasing for non-educational purposes, please purchase directly from the NCTC.

Made by Darwin Biological in the UK under licence from the UK Health Security Agency, formerly Public Health England. NCTC is the trade mark of UKHSA.

Culture is supplied on a nutrient agar slope in a glass screw top universal bottle.

*For educational purposes ONLY*

ACDP Hazard Group 1

All bacteria are sold at customer's own risk and appropriate risk assessments must be completed under COSHH before proceeding, considering both the ACDP and COSHH regulations, but also considering the risk to young people as a susceptible group. No responsibility will be taken for any accidents resulting from misuse.

Cultures are non-returnable.

For UK educational purposes only.

Not for human consumption.

Click here to view the Safety Data Sheet

CLEAPSS have a great range of resources regarding how to safely use bacteria in schools, and the Microbiology Society offer a free Basic Practical Microbiology manual.

We advise storing in the fridge (around 4°C) as this slows down the growth. Bring up to room temperature before using. Do NOT freeze.

Our bacteria cultures are dispatched when strongly growing and should used soon after receipt. The longer a culture is kept the weaker it will be, so ideally it should be used or transferred onto fresh sterile nutrient agar/broth within 2 weeks.

Additional information about Darwin Biological's bacteria cultures can be found here.

CLEAPSS have some great resources about all aspects of storing and using bacteria cultures.

Mainland Britain

Our UK mainland delivery charges are as follows: (All figures are exc. VAT)

For next day delivery, please order by 1pm, item must be in stock. All stock levels are shown on the web, if showing as out of stock or prepared to order and required urgently, please contact us as we may have stock! Next day orders are sent by Royal Mail Special Delivery which is a signed for service, please ensure someone is available.

Drosophila are always dispatched on a Monday, please advise when ordering your preferred delivery week.

Our working hours are 9am - 3pm Monday - Thursday, 9am - 12pm Friday. Orders received outside these hours will be processed the next working day; orders are only dispatched Monday-Thursday (Monday-Wednesday for perishable items). Hours vary during school holidays but we are usually available via email.

*Autumn Half Term Closure: 21st - 28th October 2026 Inclusive*

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Northern Ireland

Sadly, due to the UK leaving the EU, we can no longer supply Northern Irish customers with any products the have codes starting with an 'L' or 'P'. This is due to the requirement for all live or preserved products to have an import licence specific to the customer purchasing and the product being purchased. As each licence takes 2 weeks to obtain, and involves a considerable amount of paperwork, we have made the difficult decision to stop offering these products to Northern Irish customers. We can still offer equipment, i.e. products with an 'E' code, as these simply require customs documentation.

We apologise for the inconvenience and if the legislation changes we will happily review our decision.

British Islands

Delivery charges to the Isle of Man, Channel Islands (including Jersey & Guernsey), Shetland, Orkney and all the other islands we've missed, are the same as to mainland Britain (see above). The main difference is that delivery is likely to take a little longer, and for this reason we cannot guarantee next day delivery.

In addition, we cannot ship any liquids, so any 'wet' specimen ordered will be sent vacuum packed rather than in a jar.

Click here for contact information >>

Click here for our returns policy >>