Immucor Inc., which makes blood bank reagent systems and markets a cellular assay system to monitor disease in HIV patients, made a $25 million tender offer to Gamma Biologicals Inc., which manufactures and sells in vitro diagnostic reagents.

"The acquisition will not lead Immucor away from its core business, which is fully automated transfer services," said Laure-Anne Bauwens, spokeswoman for Norcross, Ga.-based Immucor. "Rather, it is expanding our reagent side. We have some reagent products, but now we are able to offer more to our customers. Gamma Biologicals uses gels, for instance, which we don't."

David Hatcher, president and CEO of Houston-based Gamma, called the deal "a beautiful fit."

Under the tender offer, due to close in about five weeks, Immucor's subsidiary, Gamma Acquisition Corp., would acquire all outstanding shares of Gamma Biologicals for $5.40 per share, followed by a cash merger at the same price. The offer is not conditional upon financing.

Immucor, focused on automated instruments, sells the IMAGN 2000 for monitoring HIV. The system tests for enumeration of CD4+ and CD8+ T-cell lymphocytes, leukocytes and CD34+ stem cells. The product was developed by Biometric Imaging Inc., of Mountain View, Calif. Mary Welch