Problems of DNA-Losses During in vivo Isolation of Vicia faba Root Meristem Nuclei

抄録

The investigation was directed to give information about a possible DNA loss during in vivo isolation of nuclei from the Vicia faba root-tip meristem, using the isolation method from Kuehl. The relative DNA-content of isolated nuclei was compared with that of nuclei from squash preparations by means of Feulgen-micro-photometry.
As statistical problems nearly become unsurmountable measuring all nuclei phases, and as there is a selection of special nuclei phases during isolation, S-phase nuclei were labelled by incorporating ³H-thymidine. The measurement only of unlabelled nuclei leads to pure G₁- and G₂- phase values. The finding, that isolated nuclei have maximal 4% lower values than nuclei fixed in situ, can hardly be inter-preted as a real DNA loss, because of systematic errors originating from the methods.