Purification of DNA from lambda phage
ml μltracentrifuged media.
Alternative protocol for lambda DNA preparation:
After step II A (RNase and DNase digestion)add 2.9 g NaCl and 5 g PEG-8000 to each 50 ml tube (be careful to exclude clumps of PEG-8000,which are hard to dissolve.)Shake
Preparation of Phage Lambda DNA
The isolation of phage DNA from a purified phage preparation simply involves the removal of the proteins of the phage particle. This is done most easily by phenol extraction (Method A). The large amounts of high quality DNA needed for use
λdg
通过特殊转导作用导入参与乳糖发酵的基因的缺陷性λ噬菌体。 dg系 defective galactose-transdu-cingλ phage的缩写。它是一种转导噬菌体。由于λ噬菌体的 DNA和细菌染色体 DNA之间发生重组，细菌染色体上的控制乳糖代组的基因参入了λ噬菌体基因组中，而使噬菌体基因组的一部分丧失成为缺陷性噬菌体。因此，单独进行感染时不发生正常的噬菌体增殖。如用适当的方法使没有发酵乳糖能力的大肠杆菌溶原化，则该大肠杆菌便具有发酵乳糖的能力。