How does a fast-growing biosciences company get $105.16 million in a hurry?

Throw an additional 5.46 million shares on the market and sell them all for the announced price of $22.80 each.

“We are very pleased at the reception of our offering,” said David Dodd, president and chief executive officer of Serologicals Corp. “Demand for our shares was significant.”

The public stock offering, launched last week, closed Tuesday and pumped $105.16 million of net proceeds into the Atlanta-based biosciences company.

About $80 million will be used to pay off debt, including some of the $28 million used to build a 44,000-square-foot manufacturing plant in Lawrence’s East Hills Business Park.

The plant, with about two dozen employees, already is producing Ex-Cyte, the company’s cornerstone product. The plant won’t officially be on line until its operations can be validated, which would clear the way to release products to suppliers for use in research labs and other bioscience operations worldwide.

Pharmaceutical companies use Ex-Cyte, derived from serum drawn from slaughtered cattle, to speed growth of cells for use in researching and creating drugs. The product provides annual sales of about $30 million.

Serologicals plans to use the remaining $25.16 million generated by the stock offering — $13.7 million more than the company had been expected — for general corporate expenses.

“We will have additional resources to pursue our strategic growth strategy,” Dodd said.

So far this year, Serologicals has geared up for the validation of the Lawrence plant — a milestone expected to be reached early next year — and agreed in September to buy Upstate Group, a research-and-development operation. In April 2003 the company acquired Chemicon International Inc., another R&D outfit.

Serologicals hasn’t settled on a specific growth plan for 2005, said Bill Davis, a company spokesman. But he’s confident that whatever investments are made should pay off for the Lawrence area.

“It could be future acquisitions,” he said. “It could be licensing agreements, (and/or) distribution efforts with other companies that we do business with.

“We’re going to be using these moneys to further grow the company, and that’s better for Lawrence because, hopefully, we’ll be continuing to grow our sales base. And the more we sell, the more (the) Lawrence (plant) can make.”

Serologicals shares closed Tuesday at $22.82, down 15 cents, or 0.65 percent, on the Nasdaq National Market.