Investors looking for stocks in the Medical - Biomedical and Genetics sector might want to consider either Qiagen (QGEN) or Illumina (ILMN). But which of these two stocks offers value investors a better bang for their buck right now? We'll need to take a closer look.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great grade in the Value category of our Style Scores system. The proven Zacks Rank puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.Qiagen has a Zacks Rank of #2 (Buy), while Illumina has a Zacks Rank of #3 (Hold) right now. The Zacks Rank favors stocks that have recently seen positive revisions to their earnings estimates, so investors should rest assured that QGEN has an improving earnings outlook. However, value investors will care about much more than just this.Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.The Value category of the Style Scores system identifies undervalued companies by looking at a number of key metrics. These include the long-favored P/E ratio, P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that help us determine a company's fair value.QGEN currently has a forward P/E ratio of 21.07, while ILMN has a forward P/E of 63.34. We also note that QGEN has a PEG ratio of 1.84. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. ILMN currently has a PEG ratio of 2.Another notable valuation metric for QGEN is its P/B ratio of 3.94. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. By comparison, ILMN has a P/B of 11.62.These metrics, and several others, help QGEN earn a Value grade of B, while ILMN has been given a Value grade of C.QGEN sticks out from ILMN in both our Zacks Rank and Style Scores models, so value investors will likely feel that QGEN is the better option right now. Zacks' Top Picks to Cash in on Artificial Intelligence In 2021, this world-changing technology is projected to generate $327.5 billion in revenue. Now Shark Tank star and billionaire investor Mark Cuban says AI will create "the world's first trillionaires." Zacks' urgent special report reveals 3 AI picks investors need to know about today.See 3 Artificial Intelligence Stocks With Extreme Upside Potential>>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report QIAGEN N.V. (QGEN): Free Stock Analysis Report Illumina, Inc. (ILMN): Free Stock Analysis Report To read this article on Zacks.com click here.