The Washington area's biotechnology industry will go on a hiring binge in 1988, local executives say, as firms ready themselves for entry into commercial markets.

Nova Pharmaceuticals Corp. of Baltimore, one of the area's largest biotech firms, plans a 25 percent increase in its staff of 155 to fill a broad range of new positions in everything from clinical research to regulatory affairs.

Smaller firms are expanding as well. Digene, a privately held manufacturer of DNA testing kits that is based in College Park, began 1987 with 10 full-time employes and hopes to end 1988 with 40.

"This year we expanded into production development," said Digene President Leon Taub. "Now we're moving into production." In the spring, Digene hopes to market its first test kit, a DNA probe to detect CMV, an often fatal virus common to AIDS patients and others with weakened immune systems.

The local biotech hiring surge reflects a national trend; the biotech industry plans staffing increases averaging 23 percent by mid-1988 and 44 percent by June 1989, according to a study released last week by the Industrial Biotechnology Association.

The American biotech industry now employs about 40,000, primarily in hundreds of small companies still in the research and development stage.

But analysts say that commercial biotechnology, which began 10 years ago with the first experiments in gene-splicing, is about to undergo a massive reorientation toward product development and commercial sales. As evidence of how the industry has matured, IBA President Richard Godown pointed out that his association's survey included positions in sales training, licensing and investor relations "that were not even part of the bio technology work force two years ago."

Locally, for example, Genex Corp. of Gaithersburg paved the way for the commercial sale of the firm's line of specialty bioengineered proteins by acquiring Massachusetts-based Xydex Corp. in November, a purchase that brought an experienced sales and marketing network to the company. Genex also plans to hire several additional employes in 1988.

The IBA survey also found that firms looking to hire new employes had the most difficul ty finding biochemical engineers, research managers, patent attorneys and immunoengineers. Positions in oversupply, according to the survey, are biologists and organic chemists.

The study found salary increases averaging 6.9 percent in 1987 with projections for 1988 predicting increases of approximately 6.7 percent.

Exact figures were not released, but some executives say that even with those increases, salaries in the industry -- especially among smaller companies -- lag behind those offered by the large pharmaceutical companies.