BME PhD Preliminary Exam Announcement for Mary Micere Wanduka (Dr. Jacqueline Linnes, Advisor)

Title: Towards Field-Ready Lyophilized Loop-Mediated Isothermal Amplification (LAMP) reagents for Point-of-Care Diagnostics

Everyone is invited to attend the public presentation, which begins at 1:00 p.m.

Date: November 21, 2025

Time: 1:00 p.m.

Location: MRGN 129 and Zoom

Zoom link: https://purdue-edu.zoom.us/my/jlinnes

Committee members: Dr. Jacqueline Linnes (chair), Dr. Tamara Kinzer-Ursem, Dr. Alina Alexeenko, and Dr. Greg Sacha

Abstract:

Loop-mediated isothermal amplification (LAMP) has gained popularity in point-of-care (POC) diagnostics due to its high sensitivity, specificity, and rapid nature. LAMP’s effectiveness is dependent on the stability of Bacillus stearothermophilus (Bst) DNA polymerase, which is heavily reliant on the cold chain. Lyophilization has emerged as a solution to address cold chain challenges, including storage, shipping, and supply, yet its application in point-of-care molecular assays remains a challenge. Developing a lyophilization protocol for molecular assays has relied on trial and error, often facing challenges such as inconsistent performance, a lack of transferability, often slow and costly. Therefore, a systematic workflow that unites three complementary layers: experimental readout, predictive protein-centered degradation modeling, and post-lyophilization to reveal how formulation and processing dictate the stability of POC reagents. This research focuses on three main aims: (I) Developing a lyophilization protocol for a HIV-1 Particle diffusometry (PD)-Loop-mediated isothermal amplification (LAMP) system. (II) Develop a statistical model guided Bst 2.0 polymerase Degradation Analysis. (III) Correlating physical to molecular degradation of lyophilized LAMP systems. We completed Aim I by stabilizing our PD-LAMP system for approximately four months using trehalose. Our preliminary statistical model in Aim II is ongoing, which identified glycerol as a key driver of Bst’s degradation, while other formulation components exhibited synergistic and contributory effects, enabling the recognition of two new excipients. We will analyze the two new excipients in Aim III, linking post-lyophilization, empirical, and molecular stability to build a predictive framework for formulation design. This research serves as a gateway to downstream applications, transferable to other related fields.