Life Technologies Inc. of Gaithersburg said yesterday that its first-quarter earnings per share rose 8 percent this year, but a disappointed stock market pushed the company's shares lower

on the news.

The biotechnology research supply products company's stock fell $1.875, to $22.125, on volume of 110,000 shares.

The company said its operating earnings increased by 19 percent and revenue was up 16 percent. The earnings per share rose more slowly because the number of shares rose, largely because of insiders cashing in their stock options and convertible debentures to capture a special dividend the company declared in February.

George Shipp, an analyst for Scott & Stringfellow in Norfolk, Va., said the market's negative reaction surprised him. "Most companies would beg for a first quarter like this in the first quarter of 1991," he said.

Three months ended 3/31/91

F: ... ... Revenue ..... ... ...Net... ... ... ... Share

'91... ... 43,686,000.. ... ...4,006,000 ... ... 0.27

... 37,708,000.. ... ...3,508,000 ... ... 0.25

change... .... +15.9... ... ... ...+14.2 ... .... +8.0