We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us

Download Mobile App


ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.

Novel Diagnostic Test Developed for Sickle Cell Disease

By LabMedica International staff writers
Posted on 08 Sep 2014
Print article
Image: Scientists have developed a simple new test for sickle cell disease that provides results in just 12 minutes and costs as little as USD 0.5 — far simpler, faster, and cheaper than current tests (Photo courtesy of Dr. A. Kumar and Harvard University).
Image: Scientists have developed a simple new test for sickle cell disease that provides results in just 12 minutes and costs as little as USD 0.5 — far simpler, faster, and cheaper than current tests (Photo courtesy of Dr. A. Kumar and Harvard University).
Researchers have developed a simple, rapid, low-cost test for sickle cell disease (SCD) that could enable large-scale global screening also of children in underprivileged regions, such as those in Africa and India.

A team led by Harvard University (Cambridge, MA, USA) postdoctoral fellow Ashok Kumar, PhD, and Prof. George Whitesides have developed a low-cost, novel test for SCD that provides results in just 12 minutes. “The tests we have today work great, they have a very high sensitivity,” said Dr. Kumar, “But the equipment needed to run them costs in the tens of thousands of dollars, and they take hours to run. That’s not amenable to rural clinics, or even some cities, where the medical infrastructure isn’t up to the standards we see in the US.” Although extensive analysis will be needed to determine whether the test is accurate enough to use in the field, when run against over 50 known clinical samples — 26 positive and 26 negative — it showed good sensitivity and specificity.

A chance meeting with Dr. Thomas Stossel, MD at Harvard-affiliated Brigham and Women’s Hospital had steered Dr. Kumar into focusing on SCD. “Initially, we started off working on malaria, because we thought when parasites invaded the cells, it would change their density,” he said, “But when I met Tom Stossel on a panel at the Harvard Medical School, he said, ‘You need to work on sickle cell.’ He’s a hematologist by training and has been working with a nonprofit in Zambia for the past decade, so he’s seen the need from the lack of a diagnostic tool.”

The method design is simple and works by connecting two long-understood principles. First, sickle cell red blood cells (RBCs) are denser than normal RBCs; second, many polymers, when mixed in water, automatically separate into layers ordered by density. Conventional methods to separate cells by density have relied on layering liquids with different density by hand. The new insight was to use the self-forming density layers. “When you mix the polymers with water, they separate just like oil and water,” said Dr. Kumar, “Even if you mix it up, it will still come back to those layers.” When the test was run with infected blood, the results were unmistakable. While healthy RBCs settled in the tubes at specific levels, the dense RBCs from blood infected with sickle cell settled significantly lower. The band of RBCs could clearly be seen by eye.

Next, “We wanted to make the test as simple as possible,” Dr. Kumar explained, “The idea was to make it something you could run from just a finger prick. Because these gradients assemble on their own, that meant we could make them in whatever volume we wanted, even a small capillary tube.” The design they chose is barely larger than a toothpick. In the field, running the test is as simple as uncapping the tube, pricking a patient’s finger, and allowing the blood to wick into the tube.

“There were studies recently that showed in sub-Saharan Africa between 50%-90% of the children born with sickle cell disease die before the age of 5,” said Dr. Kumar, “Whereas in the US people don’t die from this disease as children, they can still live a full life. So my hope is that if this test is effective, it can make [at least] some small dent in those numbers.”

The test is described in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS), September 2, 2014, online before print.

Related Links:

Harvard University

Platinum Supplier
Ultra-Low PSA Control
Prostate-Specific Antigen Control
ALLERgen Specific IgE ELISA Kits
HLA-B27 Real Time PCR Test

Print article


Clinical Chem.

view channel
Image: Electrochemical cells etched by laser on wooden tongue depressor measure glucose and nitrite in saliva (Photo courtesy of Analytical Chemistry)

Biosensor-Fabricated Wooden Tongue Depressor Measures Glucose and Nitrite in Saliva

Physicians often use tongue depressors to examine a patient's mouth and throat. However, it is hard to imagine that this simple wooden tool could actively assess a patient's health. This idea has led to... Read more


view channel
Image: Newly observed anti-FSP antibodies have also been found to predict immune-related adverse events (Photo courtesy of Calviri)

First Blood-Based Biomarkers Test to Predict Treatment Response in Cancer Patients

Every year worldwide, lung cancer afflicts over two million individuals and almost the same number of people succumb to the disease. This malignancy leads the charts in cancer-related mortalities, with... Read more


view channel
Image: The rapid MTB strip test for tuberculosis can identify TB patients within two hours (Photo courtesy of Chulalongkorn University)

Rapid MTB Strip Test Detects Tuberculosis in Less Than an Hour without Special Tools

Tuberculosis (TB), a highly infectious disease, continues to pose significant challenges to public health worldwide. TB is caused by a bacterium known as "Mycobacterium tuberculosis," spreading through... Read more


view channel
Image: The UNIQO 160 (CE-IVDR) advances diagnostic analysis for autoimmune diseases (Photo courtesy of EUROIMMUN)

Novel Automated IIFT System Enables Cutting-Edge Diagnostic Analysis

A newly-launched automated indirect immunofluorescence test (IIFT) system for autoimmune disease diagnostics offers an all-in-one solution to enhance the efficiency of the complete IIFT process, comprising... Read more


view channel
Electronic biosensor uses DNA aptamers for detecting biomarkers in whole blood samples (Photo courtesy of Freepik)

Electronic Biosensor Detects Biomarkers in Whole Blood Samples without Addition of Reagents

The absence of robust, reliable, and user-friendly bioanalytical tools for early and timely diagnosis of cardiovascular diseases, particularly sudden cardiac arrest, leads to preventable deaths and imposes... Read more


view channel
Image: The global HbA1c testing devices market is expected to reach USD 2.56 billion in 2027 (Photo courtesy of Freepik)

Global Hemoglobin A1c Testing Devices Market Driven by Rising Prevalence of Diabetes

Hemoglobin A1c (HbA1c), or glycated hemoglobin, refers to hemoglobin with glucose attached. HbA1c testing devices are used for blood tests that determine average blood glucose, or blood sugar levels.... Read more
Copyright © 2000-2023 Globetech Media. All rights reserved.