JenLab 2P Microendoscope – High-NA GRIN Lens-Based Two-Photon Microendoscopy System

Overview

The JenLab 2P Microendoscope is a compact, high-resolution two-photon microendoscopy system engineered for minimally invasive, depth-resolved optical sectioning in living biological tissues. At its core lies a custom-fabricated high-numerical-aperture (high-NA) gradient-index (GRIN) lens assembly—designed and manufactured in Germany to meet stringent optical tolerances required for nonlinear excitation efficiency and subcellular spatial fidelity. Unlike conventional confocal endoscopes, this system leverages near-infrared (NIR) femtosecond pulsed excitation (typically 700–1000 nm) to induce two-photon fluorescence (TPF) and second-harmonic generation (SHG), enabling intrinsic contrast from endogenous fluorophores (e.g., NAD(P)H, FAD) and structural proteins (e.g., elastin, collagen). Its miniaturized probe geometry—diameters ranging from 0.5 mm to 1.4 mm—permits intradermal insertion and longitudinal monitoring in murine models, human skin in vivo, and engineered 3D tissue constructs without surgical exposure. The system is not standalone; it integrates seamlessly with JenLab’s DermaInspect® clinical platform or the research-grade MPTflex multiphoton workstation, sharing laser sources, galvo-scanning optics, and spectral detection modules.

Key Features

• High-NA GRIN lens probe optimized for efficient two-photon excitation and signal collection at depths up to 200 µm in human stratum corneum and up to 500 µm in murine dermis
• Diffraction-limited lateral resolution ≤ 0.7 µm and axial resolution ≤ 2.5 µm under optimal alignment and immersion conditions
• Real-time optical sectioning capability with frame rates up to 30 fps (512 × 512 pixels) for dynamic physiological monitoring
• Integrated dual-channel spectral detection: simultaneous acquisition of TPF (e.g., elastin, GFP) and SHG (e.g., collagen I/III) signals with configurable bandpass filters
• Motorized focus-tuning mechanism for precise axial scanning across tissue layers without physical probe repositioning
• Biocompatible stainless-steel or polymer-coated probe housing compliant with ISO 10993-5 cytotoxicity standards for short-term in vivo use

Sample Compatibility & Compliance

The 2P Microendoscope supports a broad spectrum of biological specimens—including ex vivo human skin biopsies, intravital murine models (e.g., dorsal skinfold chamber, orthotopic tumor grafts), 3D organotypic skin equivalents, and stem cell-derived epithelial-mesenchymal co-cultures. It is routinely deployed in GLP-aligned preclinical studies where longitudinal imaging must comply with OECD Test Guidelines 402 (acute dermal toxicity) and 410 (repeated dose dermal toxicity). For clinical dermatology applications, the probe design adheres to IEC 60601-1 general safety requirements and IEC 62304 software lifecycle standards when operated via DermaInspect®. Data acquisition workflows support audit-trail-enabling metadata tagging (time, depth, laser power, detector gain) required under FDA 21 CFR Part 11 for regulated cosmetic efficacy trials.

Software & Data Management

Acquisition and post-processing are managed through JenLab’s proprietary MPTsoft v5.x suite, which provides real-time image reconstruction, Z-stack generation, spectral unmixing, and time-lapse registration. All raw data are saved in vendor-neutral HDF5 format with embedded TIFF-compatible metadata tags, ensuring compatibility with open-source platforms such as ImageJ/Fiji, Python-based napari, and MATLAB-based Bio-Formats. The software includes built-in tools for quantitative morphometric analysis—including collagen/elastin ratio mapping, epidermal thickness profiling, and fluorescent protein expression kinetics—calibrated against NIST-traceable reference phantoms. Exported datasets retain full provenance for traceability in regulatory submissions.

Applications

• Intratissue imaging of small animal models: longitudinal tracking of tumor angiogenesis, immune cell infiltration, and metastatic niche formation
• Clinical diagnostic dermatology: non-invasive stratification of photodamage, melasma, and early-stage non-melanoma skin cancers via intrinsic contrast
• Tissue engineering: real-time assessment of extracellular matrix remodeling and keratinocyte differentiation in 3D skin equivalents
• Cosmetic research: quantification of anti-aging compound penetration kinetics and impact on collagen synthesis dynamics
• In situ drug monitoring: spatiotemporal tracking of topically applied fluorescently labeled therapeutics across epidermal and dermal barriers
• Stem cell research: visualization of engraftment, migration, and lineage-specific marker expression in regenerative wound models

FAQ

Is the 2P Microendoscope compatible with third-party femtosecond lasers?

Yes—provided the laser delivers tunable NIR output (680–1080 nm), pulse width < 150 fs, and repetition rate ≥ 80 MHz, and interfaces via standard free-space beam coupling or fiber port (FC/APC). Integration requires optical alignment verification and power calibration per JenLab’s technical note TN-ME-02.
What is the maximum working distance and field of view?

The standard 0.9-mm-diameter probe offers a 120-µm field of view at 1× magnification; FOV scales linearly with scan mirror deflection and can be extended to 350 µm using optional relay optics. Working distance is fixed at 30–50 µm from GRIN tip to tissue surface.
Can the system perform lifetime-resolved imaging (FLIM)?

Not natively—but when paired with the MPTflex platform equipped with TCSPC module (PicoHarp 300 or Becker & Hickl SPC-150), time-domain FLIM is fully supported with 25-ps instrument response function.
Does JenLab provide validation documentation for GMP environments?

Yes—IQ/OQ protocols, calibration certificates traceable to PTB (Physikalisch-Technische Bundesanstalt), and risk assessments per ISO 14971 are available upon request for qualified installations.