Biochip Diagnoses Sepsis in Blood Samples

A new biochip will enable physicians to analyze blood for sepsis without having to send the sample to a central laboratory.

The more quickly and directly doctors recognize and treat sepsis, the greater the patient's chances of survival and speed can save lives especially in the case of blood poisoning.

A biochip device developed by scientists at the Fraunhofer Institute for Physical Measurement Techniques, (IPM; Freiburg, Germany) prepares the blood sample by separating the red blood cells from the blood and the plasma that remains is guided onto the biochip. In patients, who are suffering from sepsis, their immune system reacts by producing certain proteins. There are antibodies positioned on the chip, which fit these proteins as a key fits a lock. If the proteins are present in the blood, the antibodies fish them out of the fluid and bind them to the chip.

The apparatus distinguishes many tiny illuminated dots that show the protein was in the blood. If the patient is healthy, however, the chip remains dark. The scientists can even test for different proteins at the same time in one cycle. This is done by placing various different catcher molecules on the chip, to which specific molecules in the blood attach themselves. An ingenious selection of proven protein markers allows the investigators to obtain additional important information about the severity and cause of the illness.

Together with colleagues from a university hospital, the scientists have already successfully tested prototypes of the device and biochip. Each biochip can only be used once so they have to be affordable. Albrecht Brandenburg, PhD, a professor and group manager at IPM, said, "We predict that in the long run, with production on a large enough scale, each chip will cost no more than one euro. There are various possible applications: other conditions such as heart attacks or cancers can also be investigated in this way. What's more, the chip facilitates doping and urine testing."

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Fraunhofer Institute for Physical Measurement Techniques