What is the main difference between pBR322 and pBR310 ?

Plasmid pBR322 has been completely sequenced. [5] It characterizes pBR322 in terms of its restriction sites i.e. exact length of every fragment can be calculated. These fragments can serve as DNA markers for sizing any other DNA.It can be purified with ease and so can the recombinant DNA molecules constituted within it. There are over 40 enzymes with unique cleavage sites on the pBR322 genome. [5] The target sites of 11 of these enzymes lie within the TcR gene, and there are sites for a further two within the promoter of that gene. There are unique sites for six enzymes within the ApR gene. [5] Cloning can be done in pBR322 with the aid of any one of those 19 enzymes will result in insertional inactivation of either the ApR or the TcR markers. However, cloning in the other unique sites does not permit the easy selection of recombinants, because neither of the antibiotic resistance determinants is inactivated. [5] One of the advantages of pBR322 is that it has a high copy number.Thus an E.coli culture provies a good yield of recombinant pBR322 molecule.[4] Advantages: Much smaller insert site (~6kb) Detection is much simpler, reliable. Higher copy number i.e. 15 copies per cell Users: Model system for understanding translation and transcription of prokaryotes. Disadvantages: Conjugative Detection scheme takes time Selective pressure Size of insert is only 6kb pBR310: . The PBR-310 is intended for operation at an ambient temperature of 25 degrees Centigrade. 2. Adequate airflow should be provided to the PBR-310 to maintain the required ambient thermal conditions. 3. Ensure that the PBR-310 power supply and all equipment used with it have properly earthed ac power supplies. 4. Standard precautions against electrostatic discharge (ESD) must be followed while handling the PBR-310. Terminate unused electrical output ports with 50 ohm connected to ground. 5. The PBR-310 must be operated in a dust-free environment. Keep unused ports capped. Particular care must be taken to ensure that the optical connectors are kept clean. It is recommended that the connector surfaces and exposed parts be cleaned periodically with lint-free wipes (Texwipes® or Kimwipe® ) and talcum-free swabs soaked in optical-grade isopropyl alcohol, and then blown dry with inert dusting gas (Tech Spray® Duster 1671). Do not use freon-based cleaners. 6. Follow ESD precautions when removing or inserting pluggable optics modules. Although the modules can be removed or installed when the unit is powered up, it is recommended that the System be powered down for changing optical modules. 7. Use the USB adapter cable provided with the system to connect the serial interface to the standard USB COM port of a desktop or laptop PC read less