Lego is demonstrating this summer that role models in science and technology for girls are still fairly scarce in toy land, just as in the real world.

 An astronomer at work in Lego’s Research Institute, the toymaker’s first line to feature women in a professional setting.

An astronomer at work in Lego’s Research Institute, the toymaker’s first line to feature women in a professional setting.

The company stirred excitement this month by offering a line aimed at girls called the Research Institute, Lego’s first offering to feature women in a professional setting rather than at play or partying.

The set included three female scientists in their respective labs (without the pink frilly dresses worn by the girl Legos in the company’s best-selling Friends line).

Its introduction made news, especially given the pressure the company faced this year when a little girl’s letter went viral — she had begged Lego to produce more realistic sets for girls that gave them adventures and jobs rather than beach get-ups or baking duties.

Within days of its appearance early this month, the Research Institute — a paleontologist, an astronomer and a chemist — sold out on Lego’s website and will not be available at major retailers, including Target and Walmart.

Toys “R” Us did carry the line, but according to associates reached by telephone at two of its New York stores, it sold out at those locations as well.

A Toys “R” Us spokeswoman, Kathleen Waugh, said in an email that it would be available in about a week at the company’s Times Square and F.A.O. Schwarz stores.

Lego said the set was manufactured as a limited edition, meaning it was not mass-produced. The true enthusiast can still buy the Research Institute at Amazon.com, however, but for about three times its $19.99 retail price.