The Protein Man's Blog | A Discussion of Protein Research

A restriction enzyme (restriction endonuclease) is a special enzyme that recognizes a specific sequence of nucleotides and cleaves DNA at that specific site (restriction site or target sequence). These enzymes, which are usually found in bacteria and other prokaryotes, are considered as one of the most important tools in recombinant DNA technology since they can easily cut DNA into fragments and/or join DNA molecules from different genomes so researchers can identify and characterize genes and examine gene expression and regulation.

Bacteria are as interesting as they are diverse. Though tiny, these unicellular life forms make huge contributions to many systems and cycles. From helping break down food in your intestine; to making the molecular assist in all three of the carbon, phosphorus, and nitrogen cycles -- these little bacteria can accomplish big things. Unsurprisingly, bacteria are model organisms for research. Not only because of their diversity, but also because they are easily contained and reproduce quickly. When using bacteria for research, it is important to understand and track rates of bacterial growth within a sample. 

Isolating genomic and plasmid DNA for further investigation and downstream application (e.g. PCR, sequencing, etc.) requires totally different protocols. While isolating genomic DNA merely requires you to crack open the cell walls and purify the resulting sample, extracting plasmid DNA may be a bit trickier and more complicated than this. Here’s a rundown on how these techniques differ.

INTRODUCTION

When we speak of mitochondria, anyone with knowledge of life science could tell you of its presence in animal cells and absence in plant cells. However, it should not be forgotten that another kingdom shares this cellular powerhouse - kingdom fungi.