From their tiny Auckland office, doctors Sarita and Anand Kumble are toasting their latest success. The founders of biotech company Pictor recently signed deals with partners in India and Europe to test their unique technology, which can screen for a range of diseases from just a drop of blood. All that's required is the 2.5cm by 7.5cm test screening kit, a computer with the customised software and a flatbed scanner.

The technology's low set-up cost is a key advantage over existing testing systems, allowing the products to be used in laboratories which have only basic medical infrastructure.

Pictor has attracted some large global customers. Its screening panel for rheumatoid arthritis is being piloted in India, where hospitals and labs will offer Pictor's system at sites around the country linked to a central laboratory in Mumbai.

The system is also being evaluated for use in animal health. The world's second biggest farm animal diagnostics test manufacturer has commissioned Pictor to research whether its existing tests could be provided more cost-effectively. A third customer is a Swedish company specialising in autoimmune diagnostics.

Other potential applications include a generic wellness test, where people could have an annual checkup to screen for common diseases. Pictor has also developed a panel to screen for three of the most prevalent viral infections: Hepatitis B and C and HIV/Aids.

The Kumbles' technology is timely. The immunodiagnostic (identifying the presence and cause of disease through blood-testing) market is being driven by the need for earlier diagnosis and the availability of cost-effective tests, according to local government funding agency the Foundation for Research, Science and Technology (FRST). Diagnostic tests for autoimmune diseases - including rheumatoid arthritis - have annual worldwide sales of US$250 million ($403 million).

The Indian market represents about 10 per cent of the global market and is snowballing thanks to an expanding middle class, an increase in health insurance schemes and the privatisation of healthcare. Meanwhile, the global market for veterinary immunodiagnostics is also growing.

While the couple admit they'd like to make money from their technology, cold hard cash isn't their main driver.

Mass screening for diseases such as HIV and hepatitis could really benefit developing countries, says Sarita.

"In biotech it's not uncommon for people to go into the drug business because the market is huge and they want to solve cancer or something," says Anand. "We thought, if we could start just by diagnosing something like cancer early."

The Kumbles met and married while studying for their doctorates in biochemistry at the University of Mumbai. They moved to the United States after graduation; Anand worked for Nobel Prize winner Arthur Konberg, who identified how DNA replicates, while Sarita identified blood markers for oesophageal cancer at the Stanford University Medical School.

After the birth of their second daughter they decided on a change of lifestyle. A colleague of Sarita's, Professor Dick Bellamy, recently retired Dean of Science at the University of Auckland, suggested they try New Zealand. The couple divided their time between New Zealand and the US for a decade. In New Zealand, Anand led a team identifying genes with therapeutic value at Genesis Research, and in the US they both found jobs with several biotech companies.

Back in New Zealand, they set up Pictor in 2005. Sarita worked on the technology's proof of concept in their garage and filed initial patents by the end of the first year.

The couple used the pitching skills they learnt in Silicon Valley to attract six local investors, including two vets, raising $90,000, a figure matched by FRST. The business moved out of the garage and a second funding pitch to investors raised $140,000, allowing the Kumbles to test the concept in real life and file a full patent.

By the end of 2008 they had raised a further $460,000 from investors and a matching amount from FRST and had developed the rheumatoid arthritis screening panel. They hired an in-house software developer, a scientist and a consulting vet, and were talking to potential customers.

Pictor investor Lee Mathias, a founding director of Birthcare and diagnostic testing company Lab Tests (with which she is no longer involved), was impressed with how the Kumbles had used technology the industry "already understood".

"Then clinicians understand what they can get out of it at end, which is important because ... when you do something people understand, the business cycle is easier to anticipate. [Also] the technology doesn't require a great big machine at the end of it which makes it more accessible."

Pictor will earn revenue this year through its Indian and European contracts, and the Kumbles are now looking at potential contracts in Malaysia, South Africa, Kenya and Mexico.

Starting a company in New Zealand has been "kind of fun", says Anand, but he's aware that the country's size may present a challenge to its growth. As the technology develops, the pair believe it could attract large manufacturers looking for a way into the "street level" market they're targeting.

A sale would also allow them to concentrate on their preferred field - developing test panels for some of the most prevalent diseases in the world.