A sensitive non-isotopic assay specific for HIV-1 associated reverse transcriptase

Area of Science:

• Biochemistry
• Virology
• Immunology

Background:

• Accurate detection of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) is crucial for diagnostics.
• Traditional radioisotopic assays for RT detection have limitations in sensitivity and require extensive sample processing.

Purpose of the Study:

• To develop a sensitive, non-isotopic assay for specific detection of HIV-1 reverse transcriptase (RT).
• To improve upon the sensitivity and efficiency of existing RT detection methods.

Main Methods:

• Utilized 5-bromo-2'-deoxyuridine triphosphate (BrdUTP) in the RT reaction instead of tritiated thymidine triphosphate.
• Employed alkaline hydrolysis to degrade the template primer post-RT reaction.
• Detected single-stranded poly.(BrdU) using an immunoenzymometric assay with monoclonal anti-BrdU antibodies.
• Enhanced specificity by pre-isolating RT from virus lysate using insolubilised monoclonal anti-HIV-1 RT antibodies.

Main Results:

• The non-isotopic assay demonstrated significantly higher sensitivity, approximately 30 times greater than classical radioisotopic assays.
• A strong correlation (r = 0.96) was observed between the new assay and traditional RT determination methods.
• The assay showed a tenfold increase in analytical sensitivity due to the removal of RT inhibitors via immunological binding.
• Eliminated the need for multiple filtration steps to remove non-incorporated nucleotides, simplifying the procedure.

Conclusions:

• The developed non-isotopic assay provides a highly sensitive and specific method for detecting HIV-1 RT.
• This assay offers a significant improvement over radioisotopic methods, with enhanced sensitivity and simplified workflow.
• The assay's adaptability to microtitre plates facilitates automation, making it suitable for high-throughput screening and diagnostics.