Techniques

Amplify Your PCR Success with the Right PCR Instrument!

Nowadays, almost every biology lab has a PCR instrument — from portable, battery-operated machines, to “PCR-by-water baths”, do-it-yourself PCR, or familiar vendor packages, including those with real-time quantification or droplet digital capabilities, DNA amplification depends on a robust thermal cycler. If you are looking to upgrade, add to, or even replace the lab’s current PCR…

Read More

The Trouble with Disease Models: Case Study in Diabetes

The development of new drugs requires reliable and robust animal disease models. Since the cause of many diseases is still unknown, it is often difficult to identify adequate and predictive disease models. For example, researchers developing treatments for neuropsychiatric diseases such as Parkinson’s and Alzheimer’s face a particular challenge given the subjectivity of many of…

Read More

How to Prepare Biological Metallo-Proteins

The first thing one might notice when working with metallo-proteins is that they offer unique, colorful reactions.  These colorful reactions are based not only on the metal, but the ligand, or coordinating molecules.  Approximately 80% of proteins contain inorganic cofactors like iron (Fe) and copper (Cu) metals necessary to catalyze a reaction.  Understanding how these…

Read More

The A to Z of Histological Stains

With the use of stains and dyes, histology allows researchers to visualize particular tissue structures, chemical elements within cells, tissues and even microorganisms. The advent and evolution of histology follows that of microscopy as outlined in ‘A (very) Short History of Histology’. Histology, which means ‘tissue science’ became an academic discipline in its own right…

Read More

DNA Extraction from FFPE Tissues for NextGen Sequencing

Rapid genomic analysis offered by next generation sequencing (NGS) is ideal for personalized medicine approaches to clinical genetics, microbiological profiling, and diagnostic oncology. Many standard clinical samples are preserved as formalin-fixed, paraffin-embedded (FFPE) tissues, which presents obstacles for use in NGS analysis. FFPE tissue preservation has the benefit of keeping samples intact for histological examination…

Read More

Best Practices for DNA Shearing for NGS

Construction of high-quality sequencing libraries is pivotal to successful NGS, and DNA quality is one of the most critical aspects of library preparation. As this Nature Methods paper illustrates, DNA shearing involves appropriate and consistent fragment sizes for sensitive and accurate sequencing, and the fragments must be accurately analyzed prior to sequencing to measure molarity…

Read More

How to Properly Streak a Single Bacterial Colony

Bacteria are the workhorses of many molecular biology laboratories, and mastering the basic techniques to manipulate bacteria is an important stepping-stone towards achieving great results. When isolating DNA from bacteria, it is important to start with a single colony to ensure a homogenous population of bacteria in your culture. Isolating a single bacterial colony from…

Read More

Codon Optimization 101

The intriguing thing about protein expression is that the combination of transfer RNAs (tRNAs) that translate the 3 letter codon into an amino acid (aa) far exceeds the number of existing amino acids (aa). If you do the math correctly, the maximum number of unique combinations using the triplet code to code for the 4…

Read More

Intercalating Dyes or Fluorescent Probes For RT-qPCR?

The unique feature of real-time quantitative polymerase chain reaction (RT-qPCR) is that it associates the amplification of your target gene with a fluorescent signal in a quantifiable manner. Presently, there are numerous fluorescent tool kits/methods to consider when designing your RT-qPCR experiment. However, the two major categories to choose from are fluorescent intercalating dyes and…

Read More

Crash Course in Microbial Identification

Welcome to this crash course in microbial identification methods! Here, you will get an overview of the traditional and modern methods available for the identification of bacteria, yeast or filamentous fungi to the species level. Species level identification allows you to discriminate confidently between two species from the same genus, something that is often essential in the treatment of infectious…

Read More

Maxam-Gilbert Sequencing: What Was It, and Why It Isn’t Anymore

In the mid-1970s, two methods were developed for directly sequencing DNA: the Maxam-Gilbert sequencing (or chemical sequencing) method and the Sanger chain-termination method. Indeed, in 1980, both Walter Gilbert and Frederick Sanger were awarded The Nobel Prize in Chemistry for “their contributions concerning the determination of base sequences in nucleic acids”. Actually, each got a…

Read More

Applying Your MALDI Matrix Like a Boss

Matrix-assisted laser desorption/ionization (or simply, MALDI) is a type of mass spectrometry method. If you are new to mass spectrometry, check out our excellent primers, titled How Does Mass Spec Work and Get Out of Western Blot Hell: An intro to Mass Spec. Basically, however, mass spectrometry allows you to measure, sort, and quantify small…

Read More