Updated from 11:33 a.m. EDTInvitrogen ( IVGN) shares plunged 21% after the company announced in-line second quarter earnings, but warned that top-line growth for the rest of 2004 would be less than expected. Invitrogen announced second-quarter net income of $19.7 million, or 36 cents a share, up from $16.9 million, or 34 cents a share. On a pro forma basis, which is how Wall Street views the company, Invitrogen had record earnings of $42.2 million, or 74 cents a share, matching the Wall Street estimate and coming in 43% higher than the $29.4 million, or 56 cents a share, it had a year ago. But while the company reaffirmed earnings guidance for the rest of the year, it warned that revenue growth would slow, sending shares lower. Invitrogen said that EPS would range between 74 and 76 cents a share for the next two quarters, compared with analysts' consensus expectations of 75 cents and 77 cents a share, respectively But the company said that revenue would grow between 30% and 32% in 2004, which implies a range between $1 billion and $1.02 billion, lower than the current Wall Street estimate of $1.05 billion. Shares of the company fell $13.95 to $52.20, on 11.1 million shares traded, well more than its average daily trading volume of 894,000. Invitrogen is already missing top-line growth expectations. In the second quarter, the company said revenue came in at a record $254 million, up 32% from the year-ago $192.4 million, but lower than the Wall Street expectation of $261.5 million. The company said that its acquisition of BioReliance, which closed in February, helped boost revenue in its BioProduction business by 53%, and said revenue from its BioDiscovery business rose 19%, driven by its purchase of Molecular Probes. "During the second quarter, we saw an increasingly competitive business environment," said Greg Lucier, Invitrogen's chairman and CEO. "We continue to focus on new product introductions and enhanced selling effectiveness in an effort to stimulate revenue growth in both of our reporting segments."