2024 Undergraduate Research Showcase

Atomic Force Microscopy Approach in Studying Topographical and Mechanical Properties of Bovine Lens-Lipid Nuclear Membrane

Document Type

Student Presentation

Presentation Date


Faculty Sponsor

Dr. Laxman Mainali


The fiber cell plasma membrane of the eye lens consists of extremely high cholesterol (Chol) content, and the Chol content increases with aging. However, the role of high Chol content in lens membrane elasticity is unclear. Here, we have used the atomic force microscopy (AFM) approach to investigate the topographical images and the mechanical properties of the two-year-old bovine nuclear lens-lipid membrane (NLLM) where the cholesterol to lipid (phospholipids plus sphingolipids) ratio for NLLM is 1.9. We extracted the total lipids (lipid plus Chol) from the nucleus of the bovine lens using the monophasic extraction method. We prepared the multilamellar vesicles (MLVs) using the rapid solvent exchange (RSE) exchange method. The SUVs are then fused onto a mica surface, followed by the formation of a partial or fully supported lipid membrane where the partially supported membrane is used to measure the membrane thickness and a fully supported membrane is used to measure the force curves. We estimate the membrane compressibility modulus (KA) and Young's Modulus (E) by fitting the force curve in the elastic regime.

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