Nucleic acid Aptamers Combined with a Signal Amplification Probe, Dramatically Increases Sensitivity in ELISA like and Other Immuno-Diagnostic Assays

Ofer Nussbaum, AptaTeck bio LTD, Rehovot, Israel (Ofer@aptateck.com)

AptaTeck bio proprietary platform technology is an amplification probe for developing aptamers and antibodies based highly sensitive immuno-diagnostic assays.

Aptamers potentially can be used for monitoring targets by attaching to them a signaling element such as biotin, fluorescent dyes, electric reagent and others. However, an aptamer can carry only one such element and therefore signals obtained from such immune recognition are low and result in low sensitivity or the needs for sophisticate detection methods and readers, and therefore are usually not suitable for conventional immune assays, such as the gold standard ELISA like assays.

A proprietary platform technology developed at AptaTeck is based on a unique universal “Signal Enhancement” probe, which can easily be attached to either nucleic acid aptamers or antibodies.

This “Signal Enhancement” element is a randomized synthetic dsDNA fragment carrying a large number of detection components (biotin, fluorophore, etc.). The probe can be adjusted in length and signaling element capacity. It can easily be attached to aptamers or antibodies that are used as recognition elements. Employing Aptamers bound amplification Probe for sandwich ELISA, results in an amplified signal, leading to reliable highly specific, reproducible and sensitive assays with low limit of detection.

The aptamers-based system was tested in ELISA assays, modes employing antibodies or aptamers as for capturing and detection. In all modes, low background and highly sensitive detection of target antigens were obtained, maintaining the assay specificity and low limit of detection.

For Thrombin, the limit of detection was found to be 0.4ng/ml (20pg), while the limit of detection of a Thrombin detection ELISA kit was 4.7ng/ml (470pg). For PDGF, the limit of detection was found to be 0.32ng/ml (16pg), while the limit of detection of a PDGF detected in ELISA kit which was 0.5ng/ml (50pg).  The use of aptamers together with our efficient signal amplification probe makes aptamers feasible as antibody replacement in immune diagnostic tests such as ELISA. In addition, the system can be applied and integrated in other immuno-diagnostic platforms including Flow Cytometry, Lateral Flow, Microfluidity, Immuno arrays and Immunohistochemistry.

---

Abstract Reference & Short Personal Biography of Presenting Author
Ofer Nussbaum PhD.

• PhD at the institute of life science, the Hebrew university of Jerusalem. Subject: The mechanism of virus penetration and infection.
• Post doctoral position at NIH-NHLBI: Molecular Biology and Gene-Therapy.
• Investigator at NIH-NIAID: HIV penetration – mechanism and specifications.
• Head of Molecular Biology, XTLbio, Rehovot Israel.

For the past 6 years, specialized in RTF techniques: assay development and validated diagnostic procedures.

• Senior Scientist & Director of Clinical affairs at MND DIAGNOSTICS Ltd.
• Co-Founder and CSO at AptaTeck bio LTD, developing nucleic acid aptamers-based diagnostics.

Today:

• Co-Founder and CEO at AptuCure bio LTD, developing nucleic acid aptamers-based drugs.
• Scientific advisor