A formalin-free method for stabilizing cells for nucleic acid amplification, hybridization and next-generation...

Area of Science:

• Biopathology
• Molecular Diagnostics
• Cell Preservation

Background:

• Formalin (10% neutral buffered formalin, NBF) is a common fixative in pathology but poses carcinogenicity risks.
• Formalin substitutes are sought to mitigate health hazards.
• Streck Cell Preservative (SCP) is a formalin-free option designed to preserve cellular antigens.

Purpose of the Study:

• To evaluate the efficacy of Streck Cell Preservative (SCP) for preserving cellular nucleic acids.
• To compare SCP's impact on nucleic acid amplification, hybridization, and next-generation sequencing (NGS) against frozen controls and formalin-fixed samples.
• To assess SCP's suitability as a safer alternative to formalin in molecular diagnostic workflows.

Main Methods:

• Breast cancer cell line (SKBR-3) used as a model system.
• Cells preserved in SCP, formalin (NBF), or as frozen controls.
• Analysis included DNA extraction yield, PCR amplification, fluorescence in situ hybridization (FISH) for ERBB2/CEP17 ratio, and NGS.

Main Results:

• SCP-preserved cells showed comparable DNA yields and PCR amplification to frozen controls.
• Formalin (NBF) fixation resulted in reduced DNA yield and impaired PCR amplification.
• FISH analysis demonstrated successful hybridization and comparable ERBB2/CEP17 ratios in SCP-preserved cells, unlike NBF-fixed cells.
• SCP exhibited negligible impact on NGS testing performance.

Conclusions:

• Streck Cell Preservative (SCP) effectively maintains nucleic acid integrity for molecular analyses.
• SCP serves as a viable, safer alternative to formalin (NBF) for preserving samples for PCR, FISH, and NGS.
• SCP supports downstream molecular testing without compromising critical diagnostic information.