Rebecca S. Tirabassi received her Ph.D. in Molecular Biology studying the pathogenesis of herpesviruses. After her postdoctoral fellowship, she spent 6 years working in biotech followed by 3 years as a scientist at academic institutions. She is currently the owner of Scientific Pens, LLC, a company that provides research, writing, editing and consulting services for life scientists. In addition to writing for BitesizeBio, she is the voice behind the WiKi and Blog at Advansta.com. She also writes a personal blog entitled Mad Scientist.Crazy Mom in which she talks about surviving life with 5 kids and a menagerie of animals while trying to keep her scientific mind happy (aka occasionally writing about scientific topics that interest her - like herpesviruses).

Articles by rtirabassi:

6 ways to show your plasmid preps some TLC and get more supercoiled plasmid in return

In my last article, I explained that plasmid DNA recovered from a plasmid prep consists of few different species; supercoiled, nicked, linear and single stranded circular, and how you can distinguish them on a gel. Supercoiled DNA is the desired form of plasmid DNA; it performs better in downstream applications such as automated sequencing and…

29 Jan 2013 DNA / RNA Manipulation and Analysis

Outgrown the Roost: A Quick Protocol for Passaging Adherent Cells

Your cells have dutifully “sat down”, stuck to the bottom of the dish and replicated, replicated, replicated. You see a swarm of cells that have reached confluency and filled the entire plate. It is time to split them. This can be a relatively easy ritual, but missteps can lead to dead floating cells and the…

23 Jan 2013 Cells and Model Organisms

Outgrown the Roost: Passaging Adherent Cells, the Basic Process

Splitting, passaging, subculturing… whatever you call it, while the specifics of passaging adherent cells will depend upon the individual cell type, the basic process involves four simple steps. These basic steps are outlined below while a sample quick protocol can be found here. Rinse Cells With a Balanced Salt Solution (BSS) Prior to detaching cells…

16 Jan 2013 Cells and Model Organisms

Tips for Choosing and Using a New Primary Antibody

Finding a good primary antibody can often feel like playing Russian roulette.  Nothing is more disappointing than buying a $300 antibody that doesn’t work for your use. There are some steps you can take, however, to increase your likelihood of success. Scout out Other Labs Before you buy, ask if anyone around you or in…

14 Jan 2013 Protein Expression & Analysis

How to Calculate a DNA Primer Concentration

Calculations can be the bane of laboratory work.  Therefore, I have always looked for easy methods for getting the math done. Here are several different ways to calculate primer concentration depending on the starting material.  For all calculations, let’s assume we have 22 nmol of a DNA primer containing 16 bases. From lyophilized powder Primers…

11 Jan 2013 DNA / RNA Manipulation and Analysis

How Do YOU Stain Your DNA?

Visualization of DNA in gels is one of the most common procedures a molecular biologist can perform.  In a good day, I can run at least 4 different DNA gels!  When I was trained, ethidium bromide (EtBr) was the only viable option to easily visualize small amounts of electrophoresed DNA.  However, safer and more sensitive…

26 Oct 2012 DNA / RNA Manipulation and Analysis

Quick Protocol: How to Work Safely and Effectively with a Biological Safety Cabinet / Culture Hood

Before using any Biological Safety Cabinet (BSC) for the first time, have a person with working knowledge of the machine give you an overview of how to use the cabinet. Different labs have different protocols in regards to running the cabinet, disinfecting the cabinet, determining which pathogens that may be used in the cabinet and…

16 Jul 2012 Cells and Model Organisms

3 Ways to Abuse Biological Safety Cabinets

As we learned in my previous article, cell culture hoods have many names. As if that wasn’t enough, they are all-too-often misunderstood and mistreated, which can lead to dangerous situations harmful for both the worker and the general lab environment. Here are three common ways that workers abuse biological safety cabinets; make sure you don’t…

11 Jul 2012 Cells and Model Organisms

Biological Safety Cabinets and Culture Hoods: Know The Difference

Biological safety cabinets, laminar flow hoods, clean hoods and culture hoods are all common names for those essential pieces of equipment that you use in cell culturing. The terms are used inter-changeably, but in fact there are lots of different types of culture hoods, each of which does a different job. Knowing which is which…

09 Jul 2012 Cells and Model Organisms

How to to Speed up Commercial Midi and Maxi Plasmid Preps

Commercial kits for isolation of large quantities of plasmid DNA generally rely on standard alkaline lysis followed by an affinity chromatography column-based method to purify DNA. Compared to traditional cesium chloride banding or PEG precipitation of plasmid DNA they are a breeze, and have the added benefit of avoiding use of toxic or hazardous chemicals…

11 May 2012 DNA / RNA Manipulation and Analysis

Wasting Antibodies Doesn’t Float Your Boat? Try Floating Your Blot Instead!

Western blots may be great for visualizing protein expression, but they can be a perfect way to waste your precious antibody stocks if you follow the normal protocol. Thankfully, you don’t have to follow the normal protocol any more; here’s how to get great blots with a fraction of the antibody usage. I have tried…

09 May 2012 Protein Expression & Analysis