We’ve all accidently cut ourselves and stuck a bandage on it to stop the bleeding, then gone about our business. Usually the wound heals after a couple of days, and all is good.

On occasion, though, a simple cut can turn complicated.#-ad_banner-#

Say I’ve cut my finger and it begins to fester. I go to a doctor’s office and have a blood sample drawn and shipped to a lab for analysis. The doctor makes an educated guess as to which antibiotic might clear the infection and prescribes a 10-day supply.

By the time your blood has gone through the routine tests to identify the infection and determine the correct antibiotic, five days have passed.

But after a few days — and pills — you feel better. This time the doctor guessed right, averting a possible crisis. However, more than 250,000 people die from sepsis — the spread of bacteria from a point of infection — every year. A simple infection from a cut, or pneumonia, or any number of sources can quickly turn to sepsis — which can be deadly without prompt and proper treatment.

Until recently, doctors had to rely on antiquated tests that took days to deliver results and accurate treatment. Without a quick way to differentiate between bacteria and viruses, prescribing the right antibiotic is little more than a crapshoot.

Last year saw the emergence of a new breed of molecular diagnostics — known as in-vitro or IVD — that involves tests that identify a patient’s nucleic acids or proteins (blood or urine) or foreign objects outside the body.

These devices can diagnose sepsis and identify the proper antibiotic — right in the doctor’s office. The process takes just 2 1/2 hours after a positive blood culture and requires only five minutes of a technician’s time, with greater than 95% accuracy.

This technology truly has life-saving potential — and it’s a potential moneymaker for investors.

The global in-vitro diagnostic market was valued at $49.2 billion in 2012 and is expected to reach $69.1 billion by 2017. It is forecast to be the highest-earning segment in the $455 billion medical technology industry throughout those five years.

Right now, two companies are battling it out in this arena: One is a good investment for today, Cephid (Nasdaq: CPHD), the other possibly for tomorrow, Nanosphere (Nasdaq: NSPH).

In June, Cepheid gained FDA approval for its updated Xpert MRSA/SA BC test (part of its popular GeneXpert system), which detects infections in blood specific to causes of sepsis in hospitalized patients.

A $2.7 billion company, Cepheid recently reported third-quarter revenue of just over $100 million, a 24% increase over the same quarter a year ago. Its systems remain the most popular molecular diagnostic platform on the market, and CPHD has performed admirably, up 16% year to date and 33% over the past 12 months.

On the other hand, Nanosphere, a $106 million company, has struggled despite having more than 200 hospitals express interest in its microwave-size units — Gram-Positive Nucleic Acid Blood Culture (BC-GP) — which cost between $50,000 and $100,000 apiece. The test gained FDA approval in June 2012; however, NSPH has performed dismally, off 33% this year. Today, Nanosphere trades for $1.87, but some analysts have suggested an intermediate-term target of $5.

Considering that about 4,500 microbiology labs or hospitals in the U.S. exist that do not have molecular capabilities, there’s plenty of market left for both of these companies to tap into.

Risks to Consider: Obviously, Nanosphere is a very risky stock with huge potential. It is not for the faint of heart and should account for no more than a slice of any investor’s portfolio.

Action to Take –> Cepheid is positioned to continue gobbling up market share with its GeneExpert systems and has shown it knows how to turn a profit. It is trading at 52-week highs near $40 and has climbed steadily since its FDA approval.

P.S. When you get in on the ground floor of a promising new technology like in-vitro diagnostics, the profits that can follow can change your life forever. Andy Obermueller’s Game-Changing Stocks is devoted to finding life-changing investing ideas. Click here to see Andy’s favorite groundbreaking investment plays for 2014.