Scientists say they’ve used human test-tube baby techniques to try to save the nearly extinct northern white rhino.

In an improbable experiment, they are trying to resurrect an entire subspecies using dead males, two infertile remaining females, and some closely related southern white rhinos.

And they say they also plan to use stem-cell technology to try to create a population of pure northern white rhinos in the lab.

The European team of researchers created a few early-stage rhino embryos using a technique called intracytoplasmic sperm injection, or ICSI. They used sperm from the last northern white rhino males before they died. Some of this sperm was injected into egg cells taken from females of the southern white rhino subspecies.

They ended up with a handful of embryos, some of which could potentially be implanted into surrogate rhino mothers.

While any resulting baby rhinos would be hybrids — half northern and half southern white rhino — the experiment is a first step to re-creating an extinct subspecies in the lab, the researchers report in the journal Nature Communications.

Northern white rhinos were driven to extinction by poaching and war in the countries they once roamed — Chad, Sudan, Uganda, Congo and Central African Republic.

The last living male white northern white rhino, named Sudan, died last March. Two females remain in captivity. No northern white rhinos remain in the wild. Captive breeding programs didn't work because all of the animals had sub-par fertility.

Thomas Hildebrandt of the German Leibniz Institute for Zoo and Wildlife Research in Berlin and colleagues in the Czech Republic and Italy, as well as in Japan, turned to the same techniques used to help infertile humans and started an all-out effort to create new white rhinos in the lab.