Nav: Home

Penn State DNA ladders: Inexpensive molecular rulers for DNA research

May 26, 2017

New, license-free DNA ladders will allow researchers to estimate the size of fragments of DNA for a fraction of the cost of currently available methods. A research team of undergraduate students led by Penn State Professor of Biochemistry and Molecular Biology Song Tan and former undergraduate student Ryan C. Henrici developed two plasmids -- a circular form of DNA -- that can be cut by DNA scissors known as restriction enzymes to create the DNA ladders. The ladders can be used to estimate the size of DNA fragments between about 50 and 5,000 base pairs in length. A paper describing the research appears online May 26, 2017 in the journal Scientific Reports.

"DNA ladders, also known as DNA molecular weight markers, are among the most commonly used reagents in molecular biology research," said Tan. "They are used in any application that requires gel electrophoresis -- a technique that separates fragments of DNA by their size. We would like to offer these plasmids to the research community as a means to produce high quality DNA molecular weight markers at a low cost."

The research team created two plasmids, pPSU1 and pPSU2, that together produce DNA ladders in increments of either 100 or 1,000 base pairs, depending on which restriction enzyme is used. Researchers can easily produce in their own laboratories enough of the two ladders for 1,000 uses for under $10. In contrast, commercially available DNA ladders cost between $250 and $500 for the same amount. Additionally, unlike many currently available DNA ladders, the 100-base-pair ladders work appropriately on both agarose and polyacrylamide gels, two types commonly used in molecular biology.

"We are also excited about the possibility that the pPSU plasmids may be used around the world to further research and enhance science education in classroom laboratories," said Henrici. "This technology produces DNA ladders at less than a penny per use, a fraction of the cost of using commercially available DNA ladders."

The pPSU1 and pPSU2 plasmids used to produce the Penn State DNA ladders will be available without licensing restrictions to nonprofit academic users through the Addgene and DNASU plasmid repositories.
-end-
In addition to Tan and Henrici, the research team includes Turner J. Pecen and James L. Johnston, undergraduate students in the Schreyer Honors College at Penn State at the time the research was performed. The research is supported by the U.S. National Institutes of Health - National Institute of General Medical and the Penn State Eberly College of Science.

CONTACT:

Song Tan: sxt30@psu.edu, 814-865-3355
Barbara K. Kennedy (PIO): BarbaraKennedy@psu.edu, 814-863-4682

IMAGES:

https://psu.box.com/v/Tan5-2017

CAPTIONS:

Figure 1: Schematic of pPSU1 and pPSU2 plasmids. The 1000-base-pair (1 kb) ladder is made by cutting the two plasmids with the restriction enzyme, EcoRV. The 100-base-pair (bp) ladder is made by cutting the plasmids with PstI.

Figure 2: Gel electrophoresis images of the two Penn State DNA ladders created by cutting the pPSU1 and pPSU2 plasmids with restriction enzymes. The 100-base-pair (bp) ladder is designed to be used with both agarose and acrylamide gels.

Penn State

Related Dna Articles:

Zigzag DNA
How the cell organizes DNA into tightly packed chromosomes. Nature publication by Delft University of Technology and EMBL Heidelberg.
Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.
DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.
A new spin on DNA
For decades, researchers have chased ways to study biological machines.
From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.
Self-healing DNA nanostructures
DNA assembled into nanostructures such as tubes and origami-inspired shapes could someday find applications ranging from DNA computers to nanomedicine.
DNA design that anyone can do
Researchers at MIT and Arizona State University have designed a computer program that allows users to translate any free-form drawing into a two-dimensional, nanoscale structure made of DNA.
DNA find
A Queensland University of Technology-led collaboration with University of Adelaide reveals that Australia's pint-sized banded hare-wallaby is the closest living relative of the giant short-faced kangaroos which roamed the continent for millions of years, but died out about 40,000 years ago.
DNA structure impacts rate and accuracy of DNA synthesis
DNA sequences with the potential to form unusual conformations, which are frequently associated with cancer and neurological diseases, can in fact slow down or speed up the DNA synthesis process and cause more or fewer sequencing errors.
Changes in mitochondrial DNA control how nuclear DNA mutations are expressed in cardiomyopathy
Differences in the DNA within the mitochondria, the energy-producing structures within cells, can determine the severity and progression of heart disease caused by a nuclear DNA mutation.
More DNA News and DNA Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.