Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Bacteriophage Vectors
Bacteriophages are viruses that attack bacteria. Mainly phage lyses the bacterial cells they infect (lytic phages). But many others may choose to follow either lysogenic or a lytic cycle; in the second situation, the phage chromosome integrates into the bacterial chromosome and multiplies with the latter as prophage (temperate or lysogenic phages). The prophage can dissociate from the bacterial chromosome and follow the lytic cycle. Many bacteriophage are used as cloning vectors, the most generally used E. coli phages being λ (lambda) and M13 phages. Plasmid vectors have to be introduced into bacterial cells which are then cloned and choose for the recovery of recombinant vectors. In contrast, the phage vectors are sprightly tested to an suitable bacterial lawn (a constant bacterial-free zone in the bacterial lawn). Phage vectors show two advantages over plasmid vectors. (1) it is easier to screen a large number of phage plaques than bacterial colonies for the identification of recombinant vectors.(2) They are more efficient than plasmids for cloning of large DNA fragments; the largest cloned insert size in a λ vector is just over 24 kb, while that for plasmid vectors it is less than 15 kb λ Phage Vectors The λ genome (total 48,502 bp) contains an source of replication; genes for head and tail enzymes and proteins for DNA replication lysogeny and lysis; and single-stranded protruding cohesive ends of 12 bases (5' GGGCGGCGACCT; the other end is opposite to it; i.e.CCCGCCGCTGGA 5'). The λ genome remains linear in the phage head, but within E. coli cells the two cohesive ends anneal to make a circular molecule essential for replication. The sealed cohesive ends are known cos sites that are the sites of cleavage during and are essential for packaging of the mature phage DNA into phage heads. The λ DNA need to be larger than 38 kb and smaller than 52 kbto be packaged into phage particles. The genes for lysogeny are situated in the segment among 20 and 38 kb; the complete or a part of this segment is deleted to create λ vectors to (1) accommodate larger DNA inserts and (2) to ensure that the recombinant phage is always lytic.
Q. Symptoms of chronic gastritis? These include anorexia, chronic fatigue, and feeling of fullness, belching, vague epigastric pain, nausea and vomiting and passage of black ta
Stomata can open and close in response to changes in the CO 2 concentration inside the leaf. Would you expect stomata to open or close if the CO 2 concentration decreased? Explai
Single Cell Proteins (SCP) The term SCP was coined by Prof. Caroll Wilson (MIT) in 1966. It means the proteins obtained from microbial sources, i.e. algae, fungi, bacteria,
Personal Protective Equipment These equipments are essentially required during working to protect face, eyes, respiratory system hands and clothes. Additionally in various in
what are viruses
Q. What is the hemoglobin F? Why does the fetus need different hemoglobin? Hemoglobin F is the hemoglobin found in the hemoglobin and mammalian fetus. A is the normal hemogl
What ions must a plant obtain from the soil in order to make (a) ATP, (b) chlorophyll? (a) To create ATP (adenosine triphosphate) a plant requires a supply of phosphate io
Q What is the cyclosis? Cyclosis is a kind of interior cell movement in which an oriented flow of circulating material is created and maintained in the cytoplasm by the action
A dihybrid cross yields 320 F2 offspring. How many are expected to resemble the homozygous recessive parental?
The regulation mechanism involves: a) The hormones catecholamines (epinephrine, norepinephrine) and glucagon cause the increase in CAMP levels in cells. This CAMP activates p
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd