I agree with Gayle, that EDTA is the best way for preserving DNA and RNA. But we have switched to formic acid decal of bonemarrow biopsies for the speed-reason. And we have found that IHC has become better with some markers.
This year I tested CISH (Kappa/Lambda) on 25 BM and compared the results with the IHC. With our protocol of BM processing the CISH was successful in all cases. And the results were "clearer to read". The point is, that concentration and duration of decal in formic acid must not exceeded. There are several publications on this. Our protocol: one day fixation in NBF, next day decal in 5-10% formic acid with 5-10% formaldehyde (commercial product) for 6-8 hours, then processing over night in VIP like all other specimen. These are some of the publication, I've looked up: Brown RSD, Edwards J, Bartlett JW, Jones C, Dogan A; Routine Acid Decalcification of Bone Marrow Samples Can Preserve for FISH and CGH Studies in Metastatic Prostate Cancer; J. of Histochem. and Cytochem. Vol. 50 (1): 113-115, 2002 Janneke CA, Krijtenburg P-J, Vissers KJ, van Dekken H; Effect of Bone Decalcification Procedures on DNA in Situ Hybridization and Comperative Genomic Hybridization: EDTA is Highly Preferable to a Routinely Used Acid Decalcifier, J. Histochem. and Cytochem Vol. 47(5): 703-709, 1999 Korac P, Jones M, Dominis M, Kusec R, Mason DY, Banham AH, Ventura RA; Application of the FICTION technique for the simultaneous detection of immunophenotype and chromosomal abnormalities in routinely fixed, paraffin wax embedded bone marrow trephines, J Clin Pathol 2005;58:1336-1338 Miranda RN, Mark Hon Fong L, Medeiros LJ; Fluorescent in Situ Hybridization in Routinely Processed Bone Marrow Apirate clot and Core Biopsy Sections; Am. J. of. Pathology, Vol 145, Nr. 6, December 1994 Naresh KN, Lapert I, Hasserjian R, Lykidis D, Elderfield K, Horncastle D, Smith N, Murray-Brown W, Stamp GW; Optimal processing of bones marrow trephine biopsy: the Hammersmith Protocol, J. Clin. Pathol. 2006:59;903-911 Gudrun Lang Histolab, AKH Linz, Austria _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet