Deep in the Jungle Something Is Happening: DNA Sequencing

This blog was written by guest blogger and 2018 Promega Social Media Intern Logan Godfrey.

Only 30 years ago, the polymerase chain reaction (PCR) was used for the first time, allowing the exponential amplification of a specific DNA segment. A small amount of DNA could now be replicated until there was enough of it to study accurately, even allowing sequencing of the amplified DNA. This was a massive breakthrough that produced immediate effects in the fields of forensics and life science research. Since these technologies were first introduced however, the molecular biology research laboratory has been the sole domain of PCR and DNA sequencing.

While an amazing revolution, application of a technology such as DNA sequencing is limited by the size and cost of DNA sequencers, which in turn restricts accessibility. However, recent breakthroughs are allowing DNA sequencing to take place in jungles, the arctic, and even space—giving science the opportunity to reach further, faster than ever before. 

Gideon Erkenswick begins extractions on fecal samples collected from wild tamarins in 2017. Location: The GreenLab, Inkaterra.

Gideon Erkenswick begins extractions on fecal samples collected from wild tamarins in 2017. Location: The GreenLab, Inkaterra. Photo credit: Field Projects International.

The newfound accessibility of DNA sequencing means a marriage between fields of science that were previously largely unacquainted. The disciplines of genomics and wildlife biology/ecology have largely progressed independently. Wildlife biology is practiced in the field through observations and macro-level assessments, and genomics, largely, has developed in a lab setting. Leading the charge in the convergence of wildlife biology and genomics is Field Projects International. 

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Six (and a Half) Reasons to Quantitate Your DNA

Knowing how much DNA you have is fundamental to successful experiments. Without a firm number in which you are confident, the DNA input for subsequent experiments can lead you astray. Below are six reasons why you should quantitate your DNA.

6. Saving time by knowing what you have rather than repeating experiments. If you don’t quantitate your DNA, how certain can you be that the same amount of DNA is consistently added? Always using the same volume for every experiment does not guarantee the same DNA amount goes into the assay. Each time there is a new purified DNA sample, the chances that you have the same quantity as before are lessened. Consequently, without knowing the DNA concentration of the sample you are using, the amount of input DNA cannot be guaranteed and experiments may have to be repeated.

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PowerQuant System: Tool for informed casework sample processing decisions

CottonSwabsIdentification of a crime perpetrator on the basis of DNA fingerprinting is not as easy as some of the CSI shows on television make it out to be. A sample such as blood stain, touch sample or body fluid retrieved at a crime scene is often a challenge for DNA analysts. In many instances, the samples are limited in quantity, found in dirty conditions, exposed to harsh environmental factors and are mixtures of more than one DNA—human and/or non-human. One of the most important aspects of the workflow to successfully obtain a DNA fingerprint profile is accurate quantification of human amplifiable DNA. The more information gleaned from the sample, the better equipped the DNA analyst is to determine the best course of action for obtaining a usable short tandem repeat (STR) profile from challenging samples. Therefore, Promega has developed the PowerQuant™ System, a probe-based 4-target, 5-dye real-time PCR method to a) determine human and male DNA concentrations in a sample, b) detect possible PCR inhibitors c) identify possible mixtures and d) measure DNA integrity. Continue reading “PowerQuant System: Tool for informed casework sample processing decisions”