Here at Addgene, we often refer to plasmids as lab or experimental tools. They certainly are very handy in research, but where did these tools come from and why do they exist in nature? Read on to learn more about environmental plasmids, and how they’ve helped us develop molecular biology tools for the lab.

Restriction enzyme cloning is the workhorse of molecular cloning; however, one of its biggest limitations is that sequence modifications can only be made at restriction enzyme cut sites. The lambda red system is an alternative method that can be used for cloning or genome engineering and is based on homologous recombination. It allows for direct modification of DNA within E. coli and is independent of restriction sites. The lambda red system is derived from the lambda red bacteriophage and its use as a genetic engineering tool is frequently called recombineering - short for homologous recombination-mediated genetic engineering.  It can be used to make an assortment of modifications: insertion and deletion of selectable and non-selectable sequences, point mutations or other small base pair changes, and the addition of protein tags. It also has the flexibility to modify the E. coli chromosome, plasmid DNA or BAC DNA. 

This post was contributed by guest blogger, Jennifer Rivers, a research microbiologist specializing in bacteriology and drug resistance. 

It seems as though, nowadays, we cannot make it a full month without a new, drug-resistant ‘superbug’ making headlines in one part of the world or another. Bacterial resistance to antibiotics is certainly a topic of great concern in healthcare today, but it doesn’t have to be some looming, abstract, convoluted scientific concept. It is imperative that we all understand what antibiotic resistance is and how it develops so that we may take an active part in our own health and the health of our loved ones, and become a positive force for public health.

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This post was contributed by guest blogger, Jessica Sacher, a microbiology PhD student at the University of Alberta studying with the Szymanski lab.

Reasons to Study How a Phage Recognizes Its Host

Bacteriophages (viruses that prey on bacteria) may be the most numerous and most diverse biological entities on our planet, but we still know collectively little about how they infect and influence the evolution of their bacterial prey. Currently, receptor binding proteins (RBPs, the host recognition factors of phages) constitute one of the most popular classes of phage proteins to study. These are highly useful for the biotech industry, which is in the process of capitalizing on phage RBPs as diagnostic tools and therapeutics. In addition, the strategic use of whole phages as therapeutics, which is also gaining a lot of new traction lately (1, 2), depends on knowledge of the structure(s) a given phage will recognize on a host cell.

We’ve recently begun expanding our presence in the microbiology community. For our first concrete steps into this field, we’ve curated microbiology plasmids from the repository onto one handy Microbiology Resource page and, just a few weeks ago, we attended the American Society for Microbiology's annual meeting (ASM Microbe 2016) for the first time. Our goals at the meeting were to network with scientists in this diverse and exciting field and to find out how we can serve them better. Here’s a little bit of what we learned.