Mice with Invisible Skin: Methods, Applications, and Considerations

Effective methods for achieving transparent mouse skin

• Tartrazine dye application:

  • Apply tartrazine (FD&C Yellow 5) mixed with water to create see-through mice
  • Skin becomes temporarily transparent within minutes, resulting in mice with invisible skin
  • Allows visualization of blood vessels and organs in living mice with transparent skin
  • Non-invasive and reversible - skin returns to normal when dye is washed off

• Methylene blue dye for cancer detection:

  • Inject methylene blue intra- and peritumorally for skin cancer imaging in see-through mice
  • Enhances reflectance and fluorescence confocal microscopy for tumor detection in mice with invisible skin
  • Mimics histopathology staining patterns for accurate cancer tissue discrimination in transparent mouse skin

• Confocal laser scanning microscopy (CLSM):

  • Enables real-time monitoring of skin tumors at different depths in see-through mice
  • Allows virtual sectioning of transparent mouse skin in horizontal planes
  • Useful for diagnosing melanoma and non-melanoma skin cancers in mice with invisible skin

Application techniques

Tartrazine dye method for creating mice with invisible skin

• Mix tartrazine (yellow food dye) with water to create transparent mouse skin
• Apply the solution to mouse skin, similar to a cream or face mask, to achieve see-through mice
• Wait a few minutes for transparency to occur, resulting in mice with invisible skin
• Transparency is achieved by dye absorbing into tissues and modifying the refractive index of water

Methylene blue for cancer imaging in see-through mice

• Inject methylene blue into and around tumor areas of mice with invisible skin
• Use reflectance and fluorescence confocal microscopy for imaging transparent mouse skin
• Observe tumor vascularization in reflectance images of see-through mice
• Analyze fluorescence images for structural features similar to histopathology in mice with invisible skin

Benefits and applications of mice with invisible skin

• Non-invasive organ visualization:

  • Observe blood vessels, digestive tract movement, and brain surface vessels in living mice with transparent skin
  • Monitor biological processes in real-time without harming see-through mice

• Cancer detection and monitoring:

  • Detect and demarcate skin cancers like melanoma and squamous cell carcinoma in mice with invisible skin
  • Guide Mohs micrographic surgery in ex vivo settings using transparent mouse skin
  • Monitor tumor progression and therapeutic effects of anticancer agents in see-through mice

• Research applications:

  • Study skin cancer development in mouse models with transparent skin
  • Investigate cutaneous T-cell lymphomas like mycosis fungoides in mice with invisible skin
  • Observe abnormal tissue architecture and blood flow in carcinogenesis models using see-through mice

Limitations and considerations for mice with invisible skin

• Tartrazine method:

  • Effects are temporary and reversible in creating see-through mice
  • Potential toxicity if large amounts are applied to transparent mouse skin

• Confocal microscopy:

  • Limited imaging depth (200-300 µm) - only epidermis and upper dermis of mice with invisible skin
  • Higher laser power for deeper imaging may damage transparent mouse skin

FAQ

How are mice with invisible skin created?

Mice with invisible skin are created by applying a mixture of tartrazine (yellow food dye) and water to their skin. This non-invasive method makes the mouse skin temporarily transparent within minutes, allowing visualization of internal organs and blood vessels.

Is the process of creating transparent mouse skin harmful to the mice?

No, the process of creating transparent mouse skin is non-invasive and reversible. The tartrazine dye method does not harm the mice, and their skin returns to normal when the dye is washed off.

What are the main applications of see-through mice in research?

See-through mice are used for non-invasive organ visualization, cancer detection and monitoring, and various research applications. They allow real-time observation of biological processes, study of skin cancer development, and investigation of cutaneous diseases.

Can transparent mouse skin be used to detect cancer?

Yes, transparent mouse skin can be used to detect cancer. Methylene blue dye can be injected into and around tumor areas, and then imaged using reflectance and fluorescence confocal microscopy. This technique helps detect and demarcate skin cancers like melanoma and squamous cell carcinoma.

What are the limitations of using mice with invisible skin?

The main limitations of using mice with invisible skin include the temporary nature of the transparency, potential toxicity if large amounts of dye are applied, and limited imaging depth when using confocal microscopy. Additionally, higher laser power for deeper imaging may damage the transparent mouse skin.