What medium should be used to transport biopsy specimens?

Transport Media for Biopsy Specimens

Biopsy specimens should be placed in a sterile container for transport, with the specific medium determined by the type of analysis to be performed. 1

General Transport Principles

Primary Transport Options

• For routine histopathology (Light Microscopy):

  • 10% buffered formalin is the most commonly used fixative 1
  • Place specimen in container immediately after collection
  • Ensures proper tissue preservation and prevents desiccation

• For immunofluorescence studies:

  • Michel's transport medium is recommended 1
  • Saline-moistened gauze or filter paper for short transport times (≤24 hours) 1
  • Michel's medium allows preservation of immunoreactants for up to 28 days 2

• For electron microscopy:

  • Glutaraldehyde or other EM-specific fixative 1
  • Formalin can be used if specimen will be processed quickly 1

Transport Timing and Temperature

• Transport specimens at room temperature unless otherwise specified 1
• Deliver to laboratory as soon as possible, ideally within 2 hours 1
• Avoid extreme temperatures during transport 1

Specific Biopsy Types and Their Transport Requirements

Skin Biopsies

• For direct immunofluorescence: Michel's transport medium 1, 2
• For routine histology: 10% buffered formalin 1
• For PCR analysis: Fresh tissue preferred, but Michel's medium can preserve DNA for PCR if no other options exist 3

Renal Biopsies

• For light microscopy: 10% buffered formalin 1
• For immunofluorescence: Transport in solution (tissue culture medium) 1
• For electron microscopy: Glutaraldehyde or other EM-specific fixative 1
• Handle gently with an 18G needle or wooden stick (e.g., toothpick) to avoid crush artifacts 1

Bone Marrow Biopsies

• For cytogenetic studies: Sodium heparin tubes or transport media with sodium heparin 1
• For histopathology: 10% buffered formalin 1
• Optimal concentration of sodium heparin should be 20 IU/mL of specimen 1

Important Considerations

Container Requirements

• Use sturdy containers with secure lids to prevent leaking 1
• Avoid contamination of the outside of the container 1
• If container is visibly contaminated, clean and disinfect or place in an impervious bag 1

Common Pitfalls to Avoid

• Do not use forceps on biopsy specimens to avoid crush artifacts 1
• Avoid pulling or stretching tissue during removal from biopsy needle 1
• Do not place tissue on dry gauze (causes desiccation artifacts) 1
• Do not place tissue in ice-cold saline (causes osmotic injury) 1
• Do not freeze the entire sample unless specifically required for the analysis 1

Special Considerations

• For specimens requiring both immunofluorescence and electron microscopy, Michel's medium can be used as it preserves tissue for both techniques 2
• For molecular studies (PCR), fresh or rapidly frozen tissue is preferred, but Michel's medium can serve as a backup option 3
• When cutting specimens for multiple analyses, use a fresh scalpel or single-edged blade that has been cleansed of oil and not exposed to fixative 1

By following these guidelines, you can ensure optimal preservation of biopsy specimens for accurate diagnostic evaluation.