Assay Development
RAMP: A quantitative immunoassay platform takes shape
The immunoassay technology developed during the 1960s relies on the natural function of human proteins called antibodies, which have the ability to recognize and bind to specific analytes called antigens. Simple immunoassays, such as dipstick pregnancy tests, indicate the presence of a target analyte by producing a color change that can be visually interpreted. Such immunoassay devices are generally small, simple to use, and capable of delivering rapid results—advantages that have brought...
Nuclear protein shows promise in predicting cancer
    At the March meeting of the American Association for Cancer Research, researchers from Matritech, Inc. (Newton, MA), presented a novel marker for detecting precancerous cervical irregularities. Levels of the marker, called NMP179, were shown to correlate with the presence of cervical cancer. Detection of cancer at an earlier stage than is possible using traditional Pap smears has potential to improve current treatments. Matritech's assay is based on the company's nuclear matrix...
Design considerations for IVD clinical trials
An IVD clinical trial represents a major investment for the sponsoring company; consequently, it is important to maximize the utility of the trial. One way to accomplish this is to design the trial protocol to include several time-staggered end points that may be addressed simultaneously. This can be done if the objectives of the trial are stated in advance, the end points are well-defined, and the sample size is calculated with all objectives and end points in mind. A study with multiple end...
Dispensing systems for miniaturized diagnostics
In recent years, both the diagnostic and pharmaceutical industries have begun to seek improved methods of reagent dispensing that would enable them to reduce the amount of reagent used, improve the accuracy and repeatability of the quantities dispensed, and generally expedite the processing of assays. The forces driving the search for improved dispensing technologies include the need to increase the amount of diagnostic information that can be derived from a patient sample, and a generalized...
New prospect for detecting prostate cancer risk
    It has long been apparent to physicians that finding an associated risk factor for prostate cancer—like cholesterol for heart disease—could improve prevention, diagnosis, and treatment. In a collaborative effort with the physicians' health study at Brigham and Women's Hospital (Boston), researchers at Harvard University believe they have found one such factor. According to the study, which included about 22,000 subjects, men with high levels of insulinlike growth...
Cardiac Markers: Developers enter a new era of progress
    Photo Courtesy of Simon Fraser/Science Photo Library To the medical community's ongoing war against heart disease, the IVD industry brings to bear a legion of biochemical markers designed to speed clinical diagnoses. For physicians, these diagnostics are the essential tools they need to make a difference in their patients' health outcomes. At the head of the diagnostic ranks are the troponins—proteins that reside on the heart's thin filament of striated muscle fibers, the...
Development of monoclonal antibodies and a rapid assay for tuberculosis
  Since 1978, the increasing incidence of tuberculosis (TB) infection has reawakened awareness of this disease in developed nations.1—3 Thought to be the principal killer of the human race since antiquity, TB is even today considered "probably the largest single infectious cause of human mortality."4 Informed estimates of current infection and mortality rates are truly terrifying.5,6 Although the majority of TB infections are in Third World countries, the ease of worldwide...
Sugar-coating yields designer cell surfaces
  In the past, researchers whose work required getting a cell to express an artificial surface group could expect to endure weeks or even months of genetic engineering. Painstaking labor was required to isolate DNA, put it into a vector, run gels, transfect, culture, and so on. But for applications that require only transient expression, genetic engineering may soon have competition. Research into new methods may make it possible for scientists to produce customized cell surfaces in as...
Performance characteristics of a novel immunoassay for cancer detection
  Proteases have been implicated in a number of malignant conditions, and researchers have observed increased secretion of proteases into the interstitial fluid around growing tumors. These proteases inevitably act on proteins, including those in the coagulation cascade leading to the formation of fibrin. Furthermore, fibrin is very frequently observed at the invading periphery of malignant neoplasms.1 Malignant cells also characteristically possess high levels of plasminogen activator,...
Multiplexed testing for disease-marking synergies
    In the Flowmetrix system, a single sample can contain up to 64 discrete microsphere sets differentiated by their unique red-orange fluorescence. Each set carries the reactants of a distinct bioassay. Illustration by Keith Kasnot In the human body, an effective immune response to even the simplest antigen requires the properly orchestrated activity of tens, if not hundreds, of distinct molecules including cytokines, enzymes, and eventually antibodies. This complex system of...