Techniques

Lee Lab develops novel techniques for microscopic imaging of tissue structures and dynamics for preclinical and clinical research. Listed below are our techniques currently available for collaboration. In particular, all of these techniques are label-free (i.e., using the intrinsic contrast only, not requiring fluorescence dye or genetic modification) and thus useful for longitudinal imaging of animal models and relatively easy for clinical translation. More techniques will become available.

Label-free imaging of cellular viability

This technique obtains a 3D map of the diffusion coefficient, quantifying intracellular organelle motions at cellular resolution in vivo. As the motions critically depends on intracellular ATP synthesis, the degree of the motions is believed to represent cellular viability. Click here for more technical details.

This technique will be useful to estimate individual cells' viability in tissue or even in vivo and study how the cellular viability is affected by environmental conditions, disease progress, or ageing in a longitudinal way.

  • Dynamic range: 0.1-10.0 um2/s
  • Field of view: generally 1 mm x 1 mm (adjustable)
  • Imaging depth: up to 1 mm
  • Scanning time: 5 min per volume with our 150-kHz OCT
  • Data processing time: 1-2 days with our 64-core server

 


 

3D imaging of RBC flux and speed over capillary network

This technique traces individual RBC passage throughout a capillary network to obtain 3D maps of the RBC flux, speed, and density. Compared to the previous two-photon line scanning method, it is label-free and enables RBC flow measurement over many capillaries at a time. Click here for more technical details. 

This technique will be useful to obtain a baseline flow pattern of microvasculature and analyze the pattern to quantify flow properties such as capillary transit time heterogeneity. It will be also usable for tracing how the microvascular flow varies with disease progress or ageing in a longitudinal way.

  • Dynamic range: 1-100 RBC/s and 0.1-2.0 mm/s
  • Field of view: generally 1 mm x 1 mm (adjustable)
  • Imaging depth: up to 1 mm
  • Scanning time: 2 min per volume with our 150-kHz OCT
  • Data processing time: <1 day with our 64-core server

 


 

Rapid volumetric imaging of capillary network flux dynamics

This technique continuously obtains 3D maps of the RBC flux of a capillary network, potentially every one second, enabling us to trace changes in RBC flux over hundreds of capillaries at the same time. Click here for more technical details.

This technique will be useful to study how blood flow responds to neural activation in the capillary network level. Therefore, it would be useful to study how the brain's energy supply regulation in the microvascular level varies with disease progress or ageing in a longitudinal way.

  • Dynamic range: 1-100 RBC/s
  • Field of view: generally 0.5 mm x 0.5 mm (adjustable)
  • Imaging depth: up to 1 mm
  • Scanning time: 10 s per volume with our 150-kHz OCT
  • Data processing time: 1-2 days with our 64-core server

 


 

Listed below are techniques developed by other groups but implemented in Lee Lab for collaboration.

Nondestructive live histology of cells in tissue

This technique obtains a 3D map of neurons in the cortex. As neuronal cell bodies are optically less scattering than neighboring tissue in the cortex, the cell bodies appear dark spheres in 3D OCT images. Click here for more technical details.

This technique will be useful to observe distribution of neurons in the cortex and study how the neuronal distribution and density are affected by disease progress or ageing in a longitudinal way.

  • Contrast to noise ratio: >100
  • Field of view: up to 3 mm x 3 mm (adjustable)
  • Imaging depth: up to 1.5 mm
  • Scanning time: 1 min per thin volume with our 150-kHz OCT
  • Data processing time: <1 day with our 64-core server

 


 

Label-free angiogram with single-capillary resolution

This technique obtains a 3D map of microvasculature down to the single-capillary level. As blood flow makes larger changes between repeated OCT images, blood perfusion appears bright in the OCT speckle variation map. Click here for more technical details.

This technique will be useful to study how microvascular structures are affected by physiological changes, disease progress, or ageing in a longitudinal way.

  • Contrast to noise ratio: >100
  • Field of view: up to 2 mm x 2 mm (adjustable)
  • Imaging depth: up to 1.5 mm
  • Scanning time: <1 min per volume with our 150-kHz OCT
  • Data processing time: <1 day with our 64-core server