RESUMO
OBJECTIVE: Molecular analysis of liver biopsy samples from patients requires ideal tissue preservation and handling to yield suitable material for laboratory analysis. Biopsy size, tissue handling and preservation method all may affect the quality and quantity of DNA, RNA and protein that can be extracted from liver biopsy samples. METHOD: In the present study, murine liver biopsies were performed and stored under various conditions: snap-freezing, RNAlater and Allprotect. Yield was compared to fresh biopsy tissue. RESULTS: Fresh tissue generated the highest yield of RNA while samples subjected to the snap-freezing generated the lowest yield of RNA. Preservation in RNAlater yielded higher quantities of RNA than storage in Allprotect, particularly with larger biopsy samples. There was a non-significant trend toward improved RNA quality with RNAlater (p = 0.35). DNA and protein yield were similar with RNAlater and Allprotect under a number of handling condition. Errors in tissue handling such as delays in tissue submersion or freezing did not significantly affect tissue yields in either preservation solution. Tissue yield was unchanged with up to three freeze-thaw cycles in both solutions. Biopsy size (5 vs 2 mm) and width (15 vs 18 g) had a marked effect on tissue yield. CONCLUSION: Ideally 5-mm biopsies with 15-gauge needles should be used to maximize yield. RNAlater provided higher RNA yield with similar yields of DNA and protein and was notably cheaper and easier to handle.
