MAGNETIC DETECTION: To identify bacteria by NMR, researchers first extract total RNA from bacteria and use PCR to amplify the 16S RNA as 16S DNA, one end of which can be captured by microbeads (1–3 μm in diameter) coated with a covalently bound DNA probe. DNA conjugated to magnetic nanoparticles (20–30 nm) binds to the opposite end of the target DNA, forming a magnetic DNA sandwich that can be detected by nuclear magnetic resonance (NMR)THE SCIENTIST STAFFWhen someone shows up at the doctor’s office with signs of an infection, chances are good that the physician will diagnose the ailment using methods that have changed little during the past century. After inquiring about symptoms, the doctor might collect a sample of blood, urine, or some other bodily fluid and send it to a clinical lab where it will be cultured and examined under a microscope. If bacteria are present, the lab might conduct additional culture-based tests to determine the species and its susceptibility to various antibiotics.
Depending on the microbe’s propensity to grow in culture and the amount of it present in the sample, it can take a day or longer for the lab to identify the pathogen, and an additional one to two days to get the antibiotic susceptibility results. But in many cases it can be impractical or risky for a clinician to wait for those results before initiating treatment. Therefore, he or she will make an educated guess as to the cause of the infection and might send the patient home with a prescription for a broad-spectrum antibiotic capable of ridding the body of a number of bacterial pathogens.
This practice means that doctors sometimes prescribe antibiotics when they are not necessary, potentially leading to harmful side effects ...
