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Meet Dr. Arnold Castro – Outstanding Laboratorian, February 2012

Posted on by Curt Shannon
Photo of Dr. Arnold Castro, laboratorian at CDC
Dr. Arnold Castro has developed innovative tests to more quickly diagnose syphilis. As a result, patients may begin receiving treatment sooner.

Editor’s Note: Dr. Arnold received this honor from the Laboratory Science, Policy and Practice Program Office (LSPPPO) in the Office of Surveillance, Epidemiology, and Laboratory Services (OSELS) at CDC. We asked Dr. Castro some questions about his work: 

What do you do at CDC?           

I am a research microbiologist and I am responsible for the development of new innovative point of care (POC) rapid tests for the diagnosis of syphilis using serum, plasma or whole blood. The test is simple, inexpensive, requires no expertise to interpret the results and it is capable of determining the serological status of a patient by screening and confirming the result in a single test within 2 to 15 minutes while the patient waits at the clinical site. I also have other duties related to syphilis detection, including serving as technical advisor for the WHO syphilis Proficiency Testing Program at CDC. 

What personal experience in your work are you proudest of? 

I am very proud of the opportunity to use research to develop new diagnostic tests that would be beneficial for the public health such as the development of the rapid POC test for syphilis. This test can aid in detecting and treating pregnant women and help prevent congenital syphilis. I am also proud to have acquired three patents for my work: 1) “Modified Cardiolipin and Uses Therefore:” U.S. Patent No. 7,888,043 B2. 2); “Methods, Immunoassays and Devices for Detection of Antilipoidal Antibodies:” U.S. Patent Application Number 12/433,626; 3) “Compositions and Methods for Detecting Syphilis Using Synthetic Antigens:” U.S. Patent Application No. 13/333.849.

How does your work save lives/protect people/save money through prevention? 

In the past, the serological testing for syphilis has been performed in laboratory settings, requiring appropriate equipment and trained personnel to interpret results that may not be available for several days after the sample has been collected.  This can be a problem, especially in developing countries and in inner cities; patients may not receive treatment because they fail to return for the results of their laboratory tests.  In these cases, not only does the patient remain untreated, but the disease may be spread to others. By receiving the results more quickly through the “rapid test,” the clinician can make an immediate judgment on the necessity for treatment during a single clinic visit.

What is the biggest barrier you face in doing your work? 

The biggest barrier facing our work is how to transfer our technology to the private sector, where they have established manufacturing procedures that need to be adapted to accommodate and further the principles of our research. 

What is the most important thing for the public to know about what you do? 

The most important thing the public need to know is that their taxes are well invested in facilitating our research. Our development of new methods and techniques will in turn be beneficial to the public at large.

About Dr. Castro:  Dr. Arnold Castro served a tour of duty in the U.S. army as a medical laboratory technologist with specialty in blood banking, and he was stationed at the 42nd Field Hospital in Verdun, France and at the Regional Medical Center in Landstuhl, Germany.  He became a U.S. citizen in 1965 and worked in the private sector until 1997 in immunohematology and microbiology.  While working full time, Dr. Castro attended night school and obtained an A.A.S. degree in Chemical Technology at the New York City Technical College and a BSc in Chemistry at the University of Miami.  He received his PhD degree in Microbiology from the Veer Narmad University, Surat, India. He also attended the University of Georgia graduate school in the Environmental Microbiology department.  He met his wife Helen in New York City where she was a nurse and married in 1960.  His son is a cinematographer and video tape editor, and his daughter teaches horse riding.

Posted on by Curt Shannon

4 comments on “Meet Dr. Arnold Castro – Outstanding Laboratorian, February 2012”

Comments listed below are posted by individuals not associated with CDC, unless otherwise stated. These comments do not represent the official views of CDC, and CDC does not guarantee that any information posted by individuals on this site is correct, and disclaims any liability for any loss or damage resulting from reliance on any such information. Read more about our comment policy ».

    Can it be done with a tiny drop of blood? A needle stick? Can it “titrate”? Cani it be done on dried blood? Color change? Commercially, what does it cost ? Or just direct me to a website for specific FAQ – good work

    Dr. Castro Responds: The test can be done with a needle stick; a drop of blood is added to sample port of the device. Dry blood spot studies has not being done because the POC test is to be used in the field avoiding the necessity of sending dry blood spots to reference laboratories. A positive test is indicated by the appearance of 3 red magenta lines. One for the procedural control, one for the treponemal test and one for the nontreponemal test. The test can be read visually or with the aid of a hand held battery operated reader giving a numerical value of the density of the positive line. The numerical value correlates to the antibody titer of the test. The commercial cost for the global market is approximately $ 2.5 to $ 5 USD per test. For the US, the price currently is not being determined pending FDA license approval.

    VDRL antigen in rapid test!!! That means antigen will be coated on NC membrane. Whether this test will have improved sensitivity and specificity compared to RPR test?

    Dear Mr. Pandey
    The coating of VDRL antigen to NC is not possible. There is no method to covalently attach VDRL to solid surfaces, such as NC, ELISA plates or latex beads. The antigenic site of VDRL is the head group of cardiolipin, therefor the cardiolipin molecule need to be modified by oxidation, converting the alkene groups of the fatty acid chains of cardiolipin to carboxyl groups. The carboxyl groups are then activated and attached to amine groups of a protein carrier. The cardiolipin protein complex can then be attached to any solid surface. This POC rapid test demonstrates an equivalence to VDRL and RPR.

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