Tag Archives: ELISA technique

Diagnosing Hepatitis C

Urine Test for Diagnosing Hepatitis C

Diagnosing hepatitis C can be made simpler with an easy urine test instead of the conventional and costlier two-step approach with a blood test that is currently utilized. Scientists at University of California Irvine School of Medicine have developed a test that uses enzyme-linked immunosorbent assay (ELISA)—a common diagnostic tool when using wet lab samples—to detect hepatitis C antigens indicative of a current infection.

With the traditional blood test, the first step involves detecting anti-hepatitis C antibodies. A positive result, however, does not indicate an active infection as these antibodies will be present if a person was exposed to the hepatitis C virus (HCV) in the past and the immune system fought off the pathogen. A positive test is followed by a HCV RNA test to detect viral RNA in the blood to determine an active infection. Genotyping may also be ordered to discern the most effective treatment and predict the expected length of therapy.

Urine from 110 people and blood from 138 people was collected. The results were compared using the two approaches, in which the urine test matched the blood test results completely. The new method not only increases sensitivity and specificity, it is also less expensive as the HCV RNA test can cost up to $200. In less developed nations where skilled phlebotomists and blood-processing equipment are not readily available, a simple urine test for diagnosing hepatitis C may be a lifesaver.

Hepatitis C is a blood-borne pathogen and is acquired through blood and bodily fluids, i.e. passed from infected mother to child, sharing of needles, engaged in unprotected sex, received organ transplants before 1992 and blood transfusions before 1987. According to the World Health Organization (WHO), 130-150 million people suffer from chronic hepatitis C, of which 2.7 million are Americans. During the early stages, a person infected with HCV is asymptomatic and usually goes undetected until complications develop later, which includes cirrhosis and liver failure. Diagnosing hepatitis C effectively and efficiently can staunch transmission rates and prevent future generations from unknowingly acquiring the disease.


‘Lab-on-a-Chip’ Graduated to ‘ELISA-on-a-Chip’ with the Help of Engineers

Team of engineers and scientists at Rutgers University have developed ‘lab-on-a-chip’ technology to potentially replace expensive conventional benchtop assay laboratory tests—hence, ‘ELISA-on-a-chip’—to aid in diagnosing and treating a wide array of medical conditions, including HIV, Lyme disease, and syphilis.

Enzyme-linked immunosorbent assay (ELISA) is a common “wet-laboratory” technique that uses large amounts of bodily fluids to analyze proteins (antigens or antibodies) to determine its concentration. Apart from requiring a relatively large volume of blood sample, the ELISA method utilizes expensive chemicals and skilled technicians who have to mix the fluids and chemicals by hand, making any diagnostic test run by the technique laborious and costly.

ELISA-on-a-chip uses microfluidics technology that allows the device to use 90 percent less body fluid sample as well as one-tenth the volume of chemicals used to analyze the sample than its traditional counterpart, without compromising the accuracy and sensitivity of the results. One ‘lab-on-a-chip’ can simultaneously analyze 32 samples and measure widely varying concentrations of up to six proteins in a sample.

Apart from cutting costs (chemicals used in a standard multiplex immunoassay runs approximately $1500), animal research that halted due to lack of sufficient sample can now be resumed. A miniscule amount of cerebrospinal fluid is required in comparison to the traditional benchtop assay in order to further study central nervous system disorders, such as Parkinson’s disease and spinal cord injury. Similarly, only small samples of synovial fluid are necessary to delve into possible treatments for autoimmune joint diseases, such as rheumatoid arthritis.

Currently, the research team is exploring potential commercial applications for ELISA-on-a-chip while continually conducting large-scale controlled studies to discover other potential uses of their ‘lab-on-a-chip’ technology.