A23
New alcoholic fixative and quality of nucleic acids
Alessia Gazziero, Roberta Salmaso, Vincenza Guzzardo, Ambrogio Fassina
Department of Diagnostic Sciences and Special Therapy, University of Padova, Padova, Italy
Background
In pathology and cytopathology, fixation should preserve both cellular morphology and protein epitops, in order to permit DNA/RNA extraction of satisfactory quality. Tissues are routinely fixed in formalin (F), which causes nucleic acid chain shortage and fragmentation. We present our results concerning the use of an alcoholic-based fixative, FineFIX© (FF), in comparison to F on cytological material obtained by Fine-Needle Aspiration (FNA).
Method
15 samples from effusions and 38 FNA were divided into two parts: a part was fixed in FF (group A) and the other in F (group B) and cell blocs prepared. Immuno-Cyto-Chemistry (ICC) with a panel of commonly employed antibodies was conducted under the same conditions. DNA/RNA were extracted and compared in the two groups. PCR analysis was performed to assay DNA integrity, using the human catenin as house-keeping gene (HKG) and to assay RNA integrity, after reverse transcription, using the human beta actin as HKG.
Results
The cyto-morphology and ICC were similar in the two groups. Moreover, FF fixation preserves DNA/RNA integrity as demonstrated by successful amplification of large amplification products.
Conclusions
FF fixative demonstrated to be suitable not only for cell morphology preservation, but also for DNA/RNA extraction, allowing extensive molecular analysis of biological samples and, last, but not least, laboratory safety is better achieved with F free procedures.
