The offer of $402 per share was made in connection with Abbott's acquisition of Alere, which was completed on Tuesday.
Abbott said in an SEC filing today that the "aggregate consideration" paid regarding the merger was about $4.6 billion and that Alere is now an Abbott subsidiary.
Abbott's tender offer to purchase all outstanding shares of Alere's Series B convertible perpetual preferred stock at $402 per share is now scheduled to expire on Oct. 3.
The firm said today that it has received all regulatory clearances to close the deal that it first proposed in February 2016.
The deal ends an investigation by the SEC into certain accounting practices by Alere's foreign subsidiaries. The company also consented to a cease-and-desist order.
Under the new purchase terms, Quidel will have direct commercial responsibility for the assays run on Beckman Coulter analyzers. The deal is now valued at $680 million.
Abbott said that greater than 90 percent of the issued and outstanding shares of preferred stock had been tendered as of Sept. 15.
The CDC received clearance for a number of influenza panels and kits. Agilent's assay for postnatal CNV detection, and Abbott's hematocrit test were also cleared.
The firm extended its cash tender offer for all outstanding shares of Alere's Series B convertible perpetual preferred stock until the end of the day on Sept. 15.