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.
The pBR322 plasmid contains a gene that allow the bacteria to be resistant to the antibiotics tetracycline and amipicillin. To use pBR322 plasmid to clone a gene, a restriction endonuclease first cleaves the plasmid at a restriction site.pBR322 plasmid contains three restriction sites: PstI, SalI and ecoRI. The first two restriction sites are located within the gene that codes for ampicillin and tetracycline resistance, respectively.owever, plasmids are not limited to bacteria; they are also present in some eukaryotes (e.g., circular, nuclear plasmids in Dictyostelium purpureum). A plasmid is a circular, double stranded DNA that is usually found in bacteria (however it does occur in both eukarya and prokarya).