Type II restriction endonucleases (REases) are sequence-specific endonucleases that recognize short DNA sequences and cut the DNA at defined positions within or close to the recognition sequence. In the producer cell, the host DNA is protected by specific methylation of the recognition sequence.

Restriction enzymes

restriction endonuclease

Definition of restriction enzyme: Enzymes that cut DNA molecules at specific nucleotide sequences.

Restriction enzymes are proteins that cut DNA at short, specific sequences called restriction sites. If two individuals have differences in their DNA sequences at particular restriction sites, then the restriction enzymes will cut their DNA into fragments of different lengths.

DNA fragments are cut out of their normal position in the chromosome using restriction enzymes (also called restriction endonucleases) and then inserted into other chromosomes or DNA molecules using enzymes called ligases.

​Plasmid. A plasmid is a small, often circular DNA molecule found in bacteria and other cells. Plasmids are separate from the bacterial chromosome and replicate independently of it. They generally carry only a small number of genes, notably some associated with antibiotic resistance.

Applications of DNA sequencing technologies Knowledge of the sequence of a DNA segment has many uses. First, it can be used to find genes, segments of DNA that code for a specific protein or phenotype. If a region of DNA has been sequenced, it can be screened for characteristic features of genes.

Advantages and Limitations of Genome Sequencing

• Obtaining scientific information with potential medical implications.
• Technical accuracy.
• Protection of information.
• Lifetime use.
• Cascade testing to other family members.
• Information of value to future generations in a client’s family.

What is DNA sequencing? – Uses dideoxy nucleotides to terminate DNA synthesis. – DNA synthesis reactions in four separate tubes – Radioactive dATP is also included in all the tubes so the DNA products will be radioactive. -Yielding a series of DNA fragments whose sizes can be measured by electrophoresis.

What is the function of dideoxynucleotides in Sanger DNA sequencing? a. They act as primers for DNA polymerase.

Hence, zinc finger analysis which is related to proteins, is not required for DNA fingerprinting. So, the correct answer is ‘Zinc finger analysis’.

Methods of DNA Fingerprinting Restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) amplification of short tandem repeats (STRs) are two main DNA tests widely used for DNA fingerprinting.

DNA fingerprinting is a laboratory technique used to establish a link between biological evidence and a suspect in a criminal investigation. A DNA sample taken from a crime scene is compared with a DNA sample from a suspect. If the two DNA profiles are a match, then the evidence came from that suspect.

Southern blotting

List of blots

• Southern blot for DNA.
• northern blot for RNA.
• reverse northern blot for RNA.
• western blot for proteins.
• far-western blot for protein–protein interactions.
• eastern blot for post-translational modification.
• far-eastern blot for glycolipids.
• dot blot.

Different blotting is used to detect different type of macromolecules such as southern blotting is used for DNA analysis, western blotting is for protein analysis, northern blotting is for RNA analysis and eastern for carbohydrate detection.

The problem can be solved by three types of blotting methods: Southern blotting, Northern blotting and Western blotting.

• Southern Blotting. Southern blotting is a technique for detecting specific DNA fragments in a complex mixture.
• Northern Blotting.
• Western Blotting.

Blotting is a technique by which a macromolecule such as DNA, RNA, or protein is resolved in a gel matrix, transferred to a solid support, and detected with a specific probe. These powerful techniques allow the researcher to identify and characterize specific molecules in a complex mixture of related molecules.

1 : to spot, stain, or spatter with a discoloring substance. 2 obsolete : mar especially : to stain with infamy. 3a : to dry (something, such as writing) with an absorbing agent hastily blotted her letter. b : to remove with absorbing material blotting up spilled water. intransitive verb.

Blots are techniques for transferring DNA , RNA and proteins onto a carrier so they can be separated, and often follows the use of a gel electrophoresis.  It is a method routinely used in molecular biology for detection of a specific DNA sequence in DNA samples.

It uses hybridization techniques for the identification of the specific nucleic acids and genes. The blotting technique is a tool used in the identification of biomolecules such ad DNA, mRNA and protein during different stages of gene expression.

Western blot is often used in research to separate and identify proteins. In this technique a mixture of proteins is separated based on molecular weight, and thus by type, through gel electrophoresis. These results are then transferred to a membrane producing a band for each protein.

In Western blotting (WB), target proteins are transferred to a hydrophobic membrane after SDS-PAGE and detected using specific antibodies. After SDS-PAGE, a membrane is placed on the gel, to which the separated proteins in the gel are electrophoretically transferred.