Figure 4.

Stability, copy number and northern blots showing β-galactosidase expression in duplex and triplex carrying cells. (a) Stabilities of pAMDC61- and pAMTS 61-carrying cells are shown upto 24 generations. A graph depicting the percentage of stabilities for both plasmids is presented. After subsequent generations of growth, both type of plasmids show almost equal stabilities and stability of triplex carrying plasmids do not fall drastically (b) Copy number of cells carrying plasmids containing duplex and poly pur.pyr sequences. Lane 1, lambda/HindIII; lane 2, pAMDC61; lane 3, pAMTS61. (c) Northern blot of total RNA from duplex- and triplex-carrying cells. Duplex-carrying cells have 10-fold higher level of β-galactosidase expression than triplex carrying cells.