McIntire T L, Goldey S H, Benson N A, Braylan R C
Department of Pathology, University of Florida-College of Medicine, Gainesville 32610.
Cytometry. 1987 Sep;8(5):474-8. doi: 10.1002/cyto.990080507.
Flow cytometric analysis of DNA content was performed on nuclear suspensions prepared from fresh and from paraffin-embedded, formalin-fixed lymphoid tissues. We confirmed previous reports that it is possible to obtain nuclear suspensions from deparaffinized, formalin-fixed tissues, suitable for DNA analysis by flow cytometry. We observed a tendency for a larger coefficient of variation (CV) of the DNA measurements in the fixed tissues than in the unfixed material causing abnormalities in 2 of 19 lymphomas to become undetectable. Furthermore, samples from different paraffin blocks of a single tumor with an extra G1 (hyperdiploid) peak showed marked differences in the CV of the hyperdiploid peak while the CV of the diploid peak was similar in all samples. In both benign and malignant lymphoid tissues, the S-phase fraction was higher in paraffin-embedded tissues than in unfixed cells. This difference could be attributed to 4', 6'-diamidino-2-phenylindole dihydrochloride (DAPI), a DNA-binding dye commonly used in this technique. Nevertheless, intermediate and high grade lymphomas from paraffin-embedded tissues generally showed a greater S-fraction than low grade lymphomas, a similar observation as with unfixed tissues. Therefore, DNA content analysis of nuclei extracted from paraffin sections may be inadequate to resolve slight aneuploidy, but the measurement of S-fraction size may remain diagnostically or prognostically valuable. Large retrospective studies will be necessary to determine the clinical impact of this technique in the analysis of lymphomas.
对从新鲜以及石蜡包埋、福尔马林固定的淋巴组织制备的细胞核悬液进行了DNA含量的流式细胞术分析。我们证实了先前的报道，即有可能从脱蜡的福尔马林固定组织中获得适合通过流式细胞术进行DNA分析的细胞核悬液。我们观察到，固定组织中DNA测量的变异系数（CV）有比未固定材料更大的趋势，这使得19例淋巴瘤中有2例的异常变得无法检测到。此外，来自单个肿瘤不同石蜡块且具有额外G1（超二倍体）峰的样本，其超二倍体峰的CV显示出显著差异，而二倍体峰的CV在所有样本中相似。在良性和恶性淋巴组织中，石蜡包埋组织中的S期分数均高于未固定细胞。这种差异可能归因于该技术中常用的一种DNA结合染料4',6'-二脒基-2-苯基吲哚二盐酸盐（DAPI）。然而，石蜡包埋组织中的中高级别淋巴瘤通常比低级别淋巴瘤显示出更大的S分数，这与未固定组织的观察结果相似。因此，从石蜡切片中提取的细胞核的DNA含量分析可能不足以分辨轻微的非整倍体，但S分数大小的测量可能在诊断或预后方面仍具有价值。需要进行大型回顾性研究来确定该技术在淋巴瘤分析中的临床影响。
