Choosing a Tag for Your Protein

You have identified and cloned your protein of interest, but you want to explore its function. A protein fusion tag might help with your investigation. However, choosing a tag for your protein depends on what experiments you are planning. Do you want to purify the protein? Would you like to identify interacting proteins by performing pull-down assays? Are you interested in examining the endogenous biology of the protein? Here we cover the advantages and disadvantages of some protein tags to help you select the one that best suits your needs.

Immunofluorescent detection of HiBiT-tagged proteins in CRISPR-edited cell pools and clones using the Anti-HiBiT Monoclonal Antibody.
CRISPR-Cas9 editing knocked-in HiBiT at the endogenous locus of proteins with varying subcellular localization. Fixed CRISPR-modified clones or pools of cells were imaged by immunofluorescent staining using the Anti-HiBiT Monoclonal Antibody (red) and Hoechst dye (blue). Panel A. VCL-HiBiT pool. Panel B. SMARCA4-HiBiT clone. Panel C. HDAC2-HiBiT clone. Panel D. HSP90B1-HiBiT pool.

Affinity Tags

The most commonly used protein tags fall under the category of affinity tags. This means that the tag binds to another molecule or metal ion, making it easy to purify or pull down your protein of interest. In all cases, the tag will be fused to your protein of interest at either the amino (N) or carboxy (C) terminus by cloning into an expression vector. This protein fusion can then be expressed in cells or cell-free systems, depending on the promoter the vector contains.

Continue reading “Choosing a Tag for Your Protein”

To Sleep, Perchance to Clean

While you and I are getting some shut eye each night, things are happening in our brains. Good things. Therapeutic things.

Think of it as brainwashing of a sort. There is a multiplicity of brain activities going on during sleep, and a November 1 paper in Science shows for the first time when and where in the brain these activities occur, and how they are connected.

CSF washes through the brain.

Here’s a bit of backstory.

To assess both the progression and pathogenesis of Alzheimer’s disease (AD), as well as the efficacy of AD drugs in clinical trials, there has been interest in the concentrations of amyloid-beta (Aβ) and tau protein in cerebral spinal fluid (CSF).

Continue reading “To Sleep, Perchance to Clean”

T-Vector Cloning: Questions, Answers and Tips

Blue/White colony screening helps you pick only the colonies that have your insert.

Q: Can PCR products generated with GoTaq DNA Polymerase be used to for T- vector cloning?

A: Yes. GoTaq® DNA Polymerase is a robust formulation of unmodified Taq Polymerase. GoTaq® DNA Polymerase lacks 3’ →5’ exonuclease activity and displays terminal transferase activity that adds a 3′ deoxyadenosine (dA) to product ends. As a result, PCR products amplified using GoTaq® DNA Polymerases (including the GoTaq® Flexi and GoTaq® G2 polymerases) will contain A-overhangs which makes them suitable for T-vector cloning with the pGEM®-T (Cat.# A3600), and pGEM®-T Easy (Cat.# A1360) Vectors.

Continue reading “T-Vector Cloning: Questions, Answers and Tips”

MSI Testing of Tumor Cells for Better Tailored Treatment

3D artistic rendering of mismatch repair. Microsatellite instability (MSI)  which can result from defects in mismatch repair is a biomarker for some cancers

There are as many different cancers as there are people with cancer. Unlike infectious diseases, which are caused by pathogens that are foreign to our bodies (bacteria, viruses, parasites), cancer cells arise from our body—our own cells gone rogue. Because cancer is a dysfunction of a person’s normal cells, every cancer reflects the genetic differences that mark us as individuals. Add to that environmental influences like diet, tobacco use, the microbiome and even occupation, and the likelihood of finding a “single” pharmaceutical cure for cancer becomes virtually impossible.

But, while looking for a single cure for all cancers may not be a fruitful activity, defining a best practice for understanding the genetic and protein biomarkers of individual tumors is proving worthwhile.

Continue reading “MSI Testing of Tumor Cells for Better Tailored Treatment”

The Future of Synthetic Biology: A Recap of iGEM 2019

After attending the iGEM Giant Jamboree last year and being completely blown away by the projects presented (check out this article or this one), I didn’t think I’d be as astonished this year. I attributed part of the awe I felt over the caliber and quality of the projects to my wide-eyed naiveté, having never attended the event before. The second time around, the “first-time” novelty long worn off, I didn’t expect to feel that same level of amazement.

I couldn’t have been more wrong.

After three days of impressive presentations, I once again felt that same astonishment as I prepared to watch the presentations of the 6 finalists. With good reason—the projects presented by the six finalists completely blew my mind!

Continue reading “The Future of Synthetic Biology: A Recap of iGEM 2019”

Tales from the Trenches: Career Growth in Biotechnology

Building a successful career in the biotechnology industry is really just a series of transitions from one role to another. But the devil is in the details—when to make a change, how to create opportunities and who can be your champion as you pivot. So how do you navigate these factors to keep your career goals on course?

Bob Weiland answers a question posed by Michele Smith at the MS Biotech Alumni Symposium.

I recently attended a symposium (presented by the University of Wisconsin Master of Science in Biotechnology Program, of which I’m an alum) that addressed this topic through the lens of one individual with a storied career in the industry. Bob Weiland currently serves on the Board of Directors for CymaBay Therapeutics. He has held various roles, from sales and marketing to operations and strategy, within large, established companies (Abbot, Baxter, Takeda) and smaller ones (Pacira Pharmacueticals). He drew on this wide-ranging experience to provide advice to professionals at all career stages.

Bob began the talk by declaring that there will be points in your career when you reach a “hard spot” and will need to transition, whether to a new role, company or even industry, to meet your career goals. He suggested a good starting point is simply to be thinking about making a change. But in the same breath he emphasized, “What are you doing about it?” He identified four distinct actions that you can take to ensure role changes and career transitions support your professional growth and development.

Continue reading “Tales from the Trenches: Career Growth in Biotechnology”

How should I evaluate DNA isolated from FFPE samples to ensure success?

Part two of three. You can read part 1 here.

Formalin-Fixed Paraffin embedded (FFPE) samples are being used in increasing numbers of molecular assays. In my last blog I discussed some of the pre-analytical variables that can affect results obtained when using FFPE samples. Laboratories can increase the quality of downstream results by controlling variables where possible. While exacting control over the sample acquisition and fixation process can improve results, quality testing of incoming samples is a crucial step in assuring optimal results. There are numerous methods that can be used to evaluate the quality of samples and they can provide different information that can be used to assess sample integrity and suitability for different applications.

Continue reading “How should I evaluate DNA isolated from FFPE samples to ensure success?”

Halloween Costumes: Retro Science Style

“Back when I was in the lab…”: it seems like every former scientist has a story. Kind of like Thanksgiving Dinner among your elderly relatives, scientists are quick to one-up each other with horror stories from our days at the bench—stories that included escape artist rats, a leaky sequencing gel apparatus, and the iconic radioactively contaminated post doc.

We turned to our favorite science cartoonist, Ed Himelblau, to ask for some retro Halloween costumes based on stories of things that used to be common in the lab that don’t seem like such a great idea now. Enjoy…and if you have a few retro horror science costume ideas of your own, please share them.

Continue reading “Halloween Costumes: Retro Science Style”

A Diamond in the Rough: New Applications of Diamond Nucleic Acid Dye

Diamond™ Nucleic Acid Dye (Cat# H1181) is a safe, inexpensive and sensitive fluorescent dye option that binds to single-stranded and double-stranded DNA and RNA. Diamond™ Dye typically is used for staining electrophoresis gels to visualize nucleic acids in a similar to its carcinogenic counterpart, ethidium bromide. However Diamond™ Dye has several advantages: gels stained with Diamond™ Dye can be visualized using either UV or blue-light transilluminators. Also, a wash step after staining is not necessary when using Diamond™ Dye, unlike what is typically recommended for ethidium bromide.

Besides staining electrophoresis gels, there are other applications for this diamond in the rough. Highlighted below are two fascinating uses of this multifaceted tool: touch DNA localization and qPCR detection.

Continue reading “A Diamond in the Rough: New Applications of Diamond Nucleic Acid Dye”

Kyle Hill Explains the Science of Star Wars at the Wisconsin Science Festival

Kyle Hill poses heroically with Biotech Bucky at the Wisconsin Science Festival / Photo courtesy of WARF

With another major Star Wars film about to hit the theaters this year, sci-fi enthusiasts are abuzz with excitement to watch epic lightsaber battles and hyperspace travel. But are these sci-fi concepts more grounded in science or fiction? That is what science communicator Kyle Hill aims to explore.

A Wisconsin native, Hill graduated from Marquette University with degrees in engineering and science communication. Now he resides in Los Angeles, where he built a career writing and talking about the intersection of science and pop culture through his video series, Because Science.

This past weekend at the Wisconsin Science Festival, hundreds of fans gathered to hear Hill share his ideas on how the sci-fi concepts in the Star Wars movies aren’t that far off from actual science.

Continue reading “Kyle Hill Explains the Science of Star Wars at the Wisconsin Science Festival”