Stellar Biotechnologies Announces Receipt of Lead Purchase Order

PORT HUENEME, CA--(Marketwire - Sep 20, 2011) - Stellar Biotechnologies, Inc. "Stellar" (TSX-V: KLH) (PINKSHEETS: SBOTF) is pleased to announce they have received the first purchase order from Sigma-Aldrich under terms of the marketing agreement between Stellar and Sigma's SAFC division, disclosed in Stellar press release of August 3, 2011 (http://stellarbiotechnologies.com/investors/news_releases/index.php?&content_id=81). The initial order is for a low six figure US$ amount and will support the first phase of SAFC's 2012 marketing campaign (http://safclive.com/producing-klh-for-vaccine-use-safc-director-of-marketing-and-business-development-discusses-safcs-strategic-marketing-and-sales-agreement-with-stellar-biotechnologies/).

Sigma-Aldrich's (a Fortune 1000 Company with a $7.9B market capitalization) SAFC division will perform the final purification of high molecular weight (HMW) KLH (Keyhole Limpet Hemocyanin) from Stellar's aquaculture KLH intermediate for the growing, international therapeutic and conjugate vaccine markets. The Stellar - SAFC joint marketing and joint promotion efforts are expected to grow this market significantly over coming months.

Stellar has initiated production of the SAFC material, along with production of other grades of KLH manufactured by Stellar for its other customers. Stellar is currently delivering fully purified KLH to fill orders from existing customers, and has multiple requests for samples for evaluation from international researchers, vaccine developers and medical diagnostic companies. The Company's current manufacturing campaigns will provide product to support the SAFC marketing campaign, fill orders and build inventory to support Stellar's pre-clinical product launch in early 2012.

Stellar CEO Frank Oakes said, "Receipt of this first, significant order from SAFC represents the beginning of an important move into the HMW GMP-grade vaccine market for KLH with our new partner, a company we believe is currently the most important supplier of GMP, pharmaceutical-grade KLH in the world. With the SAFC relationship, our continuing business with other customers for Stellar's GMP-grade subunit KLH, and the anticipated launch of our preclinical immunotox diagnostic product suite, we look forward with enthusiasm to growth and further creation of shareholder value over the next year."

About Stellar Biotechnologies, Inc. Stellar Biotechnologies, Inc. (TSX-V: KLH) (PINKSHEETS: SBOTF) (www.StellarBiotechnologies.com) is the world leader in sustainable manufacturing of pharmaceutical grade KLH (Keyhole Limpet Hemocyanin). This evolutionary protein has a highly complex structure that makes it ideal for use in human and animal vaccines and diagnostic products. With partners and customers, its flagship Stellar KLH products are in the clinic, and on the way to being established as the only sustainable, long-term pharmaceutical source. Stellar Biotechnologies was founded to address the growing demand for renewable, commercial-scale supplies of high-quality, GMP-grade KLH. Stellar has developed leading practices, facilities and proprietary capabilities to address this need.

There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Readers should not place undue reliance on such statements. Except in accordance with applicable securities laws, the Company expressly disclaims any obligation to update any forward-looking statements or forward-looking statements that are incorporated by reference herein. This news release does not constitute an offer to sell, or a solicitation of an offer to buy any of the Company's securities set out herein in the United States, or to, or for the benefit or account of, a U.S. Person or person in the United States. Neither TSX Venture Exchange nor its Regulation Services Provider accepts responsibility for the adequacy or accuracy of these releases.