Salt has a molar mass of 58.44 g/mol, glucose of 180.15 g/mol. 50 grams of glucose results in 278 millimoles of glucose. 9 g of sodium chloride correspond to 154 millimoles of sodium chloride. The osmolarity of the solution of sodium chloride, however, is 308 milliosmoles / liter.
In the natural world DNA usually becomes available by death and lysis of other cells, but in the laboratory it is provided by the researcher, often as a genetically engineered fragment or plasmid. During uptake, DNA is transported across the cell membrane(s) , and the cell wall if one is present.
Each colony contains a different plasmid type, because each was grown up from a single transformed cell. What we do now is to isolate DNA from each colony (or a small growth of cells propagated from the colony), and analyze the structure of the plasmid with restriction enzymes or by DNA sequencing.