Analytical Chemistry and Chromatography Techniques
Crystallize Your Protein–DNA Complex by Optimizing These Key Parameters
Looking to engineer a crystal? Here are some key parameters to optimize to give you the maximum chance of success at crystallizing protein DNA–complexes.
Read MoreCell Counting with a Hemocytometer: As easy as 1, 2, 3…
Do hemocytometers look scary and complicated with their multiple tiny squares, boxes, and grids? Take a look at our article and see how easy it actually is to use a hemocytometer.
Read MoreMass Spectrometry in Biological Research – A Guide for Beginners
Mass spectrometry can feel intimidating. Read this easy-to-follow guide to demystify mass spectrometry and learn how it can help your research.
Read MoreAdvances to SYNTHIA™ Retrosynthesis Software and How They Have Accelerated Chemical Development at GlaxoSmithKline (GSK)
Advances to SYNTHIA™ Retrosynthesis Software and How They Have Accelerated Chemical Development at GlaxoSmithKline (GSK) Available On Demand John Jin Lim, MS Senior ScientistAPI ChemistryGlaxoSmithKline plc (GSK) John Lim (MS) leads the CASD Team at GSK Chemical Development, which uses computational tools, such as SYNTHIA™ retrosynthesis software, for the route selection process. He obtained his…
Read MoreAnalyte Binding Following Sample Filtration in HPLC
Analyte Binding Following Sample Filtration in HPLC Available On Demand Speaker Vivek Joshi Senior R&D ManagerApplications DevelopmentMilliporeSigma Vivek Joshi, PhD is an Applications and Market Adoption Senior Manager at MilliporeSigma. He develops new products and applications for products that span analytical workflows, molecular and protein science workflows, and cell culture workflows. He recently presented a…
Read MoreThe End of the Beginning for Retrosynthetic Planning
The End of the Beginning for Retrosynthetic Planning Significant advances in SYNTHIA™ opening doors for complex molecule synthesis and bench validation Available On-Demand Lindsey Rickershauser, Ph.D. Manager of Sales & MarketingCheminformatics TechnologiesMerck KGaA, Darmstadt, Germany Lindsey Hess Rickershauser, PhD, currently manages the sales and marketing for SYNTHIA™ in the Cheminformatics Technologies division of MilliporeSigma, a…
Read MoreThe Do’s and Don’ts of HPTLC
This followup article on HPTLC gives a list of dos and don’ts while performing HPTLC to achieve precise and error-free results, and avoid false positives.
Read MoreHPTLC: Basics and Instrumentation
Get robotic with HPTLC! This automated version of TLC can separate and quantify compounds – find out how!
Read MoreShould You Switch from Wet to Dried Blood Samples?
A Spot of History Most of the biomedical methods used started as a curiosity. Then the one-off gains a limited use, the technology then progresses until its use becomes widespread. Just think about the arch from the curious polished glass spheres, used by Antony Levnhook to look at animalcules, to modern microscopes. The same story…
Read MoreCrash Course in Fourier Transform Infrared Spectroscopy
Fourier transform infrared spectroscopy (FTIR) is an extremely sensitive technique for measuring the absorption and intensity of electromagnetic radiation in the infrared region of the spectrum of either a solid, liquid or gas sample. You can use FTIR to: quantify unknown compounds identify unknown compounds study the detailed structured coordination of compounds How Does Fourier…
Read MoreApplying 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 MoreHPLC Tubings and a $200.000.000 NASA Crash: Converting Between Measurement Systems
In an amazing TED-Ed video from Matt Anticole, the wild history of the metric system is explained as a very smart cartoon. Matt concluded his video with a rather positive message for the scientific community: “Nevertheless, the metric system is almost universally used in science and medicine.” It sounds great, but the key word here is…
Read MoreExamining Cell Interactions with Surface Plasmon Resonance (SPR) and Identifying Epitopes using SPR-Mass Spectrometry (MS)
Surface plasmon resonance (SPR) offers highly efficient, label-free detection for quantifying biomolecular interactions in real-time. Two exciting SPR variants that have sprung up in recent years are SPR for cellular analysis and SPR-mass spectrometry (SPR-MS). SPR for cellular analysis allows you to study how cells attach to different substrates and each other, while SPR-mass spectrometry…
Read MoreAll Charged Up: The Basics of Ion-Exchange Chromatography
Highly pure proteins are vital for successful experiments; they play roles in research as assay reagents (especially for SPR applications), therapeutic candidates, and of course, as the subjects of structural and biochemical studies. Chromatography is the science of separation and we utilize it to isolate and purify proteins based on their unique physiochemical properties. One…
Read MoreThe Importance of Metabolomics Research
Metabolomics may sound like a fictional character in the famous comic series “Asterix”, but it is very important in understanding systems biology and in clinical research against various diseases. Metabolomics is the last piece of a puzzle of omics applications following genomics, transcriptomics, and proteomics. It allows us to ask “What has happened and what…
Read MoreCritical Factors for Full Characterization of Biosimilars
Today, about half of all therapeutic drug approvals by the US Food and Drug Administration (FDA) are for biological drugs. That number is expected to rise to 75 percent by 2025. When these biologics come off patent, the gates will open for a flood of biosimilar drugs (biopharmaceutical generics) that are designed to be much…
Read MoreKey Analytical Challenges for Antibody Drug Conjugates
Currently, there are more than 75 antibody drug conjugates (ADCs) in various stages of pre-clinical and clinical development. The combination of a targeted antibody coupled with a cytotoxic small-molecule drug (via a flexible linker) makes for a lethal and specific oncologic drug product. However, an ADC is a heterogeneous cocktail of molecules with a range…
Read MorePack a Chromatography Column Like a Pro
You already learned the basics of column packing. When moving to more automated system using low pressure liquid chromatography systems, you can use pre-packed columns. But in order to compare several resins in specific conditions, and also to save money, you might need to pack your own low pressure columns. The art of packing a column…
Read MoreTo Run or to Fly: A Comparison Between HPLC and GC
Many chemical compounds, including drugs and metabolites, can be analyzed by either gas chromatography (GC) or high-performance liquid chromatography (HPLC). Because both techniques function under the same basic principles of compound separation, identification, and quantification, it can sometimes be tricky to choose one over the other. But knowing what differentiates HPLC and GC can definitely…
Read MoreTen Ways to Give Your Surface Plasmon Resonance Experiments a Hand
Surface Plasmon Resonance (SPR) is the gold standard for measuring biomolecular binding without the need for labeling (i.e., label free detection of kinetics). SPR is especially valuable because it doesn’t just provide information at the start and end of a binding event, but can be used to follow association and dissociation kinetics of biomolecules in real-time.…
Read MoreHow to Clean and Unclog Your HPLC Column
In my last article, I discussed how to best keep your lab’s HPLC running smoothly. However, even the best-maintained HPLCs and columns need periodic cleaning. Today, I’ll describe how to identify and troubleshoot a clogged HPLC column. Columns Are Finite First of all, it’s important to realize that columns do have a finite lifetime. The…
Read MoreHow to Separate Nucleotides Using Ion-paired Reverse Phase HPLC
If you work in the field of molecular biology, there is hardly a day that goes by that you don’t use nucleotides. But beyond the use of the four well-known deoxynucleotides in PCR, you can use nucleotides for several other applications. For example, kinases and phosphatases use nucleotides as substrates, and phosphotransferases transfer phosphate group…
Read MoreUnder Pressure: Tips for Keeping Your HPLC Up and Running Properly
If you’re anything like me, your biggest lab fear is working with expensive equipment prone to damage. HPLC is a wonderful tool, capable of separating, identifying, and quantifying a vast array of compounds, but it requires an attentive scientist to properly handle and maintain each component. In this article I’ll describe a few basic handling…
Read MoreUsing a Gel Filtration Chromatogram to Estimate Molecular Weight
Gel filtration chromatography (also known as size exclusion chromatography, molecular sieve chromatography, or gel permeation chromatography) is based on the differential distribution of the components in a sample between the mobile and stationary phases. Specifically, in gel filtration chromatography, this differential distribution depends on the size and shape of the components. Here, we take a…
Read MoreFTIR Spectroscopy: Every Window Needs a Good Acid Wash
Fourier Transform Infrared spectroscopy (FTIR spectroscopy) is a useful and exquisitely sensitive technique used to identify and quantify unknown compounds, as well as study fine molecular details. However, to obtain a meaningful IR spectrum, it is not only important to prepare the sample correctly but also to learn how to clean the apparatus that houses…
Read MoreGel Filtration Chromatography Media: What You Need to Know
Do you use pre-packed Superdex 75 or Superdex 200 columns for gel filtration chromatography? Ever wonder if other media could better address your purification needs? Look no further. Your quest ends here! But if you’re looking for information on gel filtration principles, check out this earlier article. Choosing a Column for your Gel Filtration Experiment…
Read MoreHow Separation Works in Column Chromatography Methods
Separation in column chromatography relies on differences. Molecules vary in size, charge, polarity, and solubility. We leverage these differences to distribute molecules between a stationary phase and a mobile phase. But because molecules are so different, it’s not possible to have a single method that works for all. In my previous article I discussed the…
Read MoreFine-Tune Your MALDI-TOF to Produce Good-looking Mass Spectra
Mass Spec is all about getting the perfect peaks. Without a good peak assigning the correct mass is impossible and you cannot make accurate identifications. Make sure you know how to adjust your MALDI-TOF instrument parameters to achieve your perfect peak. In our previous posts ‘How does Mass Spec Work’ and ‘Imaging Mass Spectrometry: the…
Read MoreThe Basics of Running a Chromatography Column
Column chromatography is a common technique used to separate individual compounds from a mixture. You can use column chromatography on both a small or large scale to isolate and purify material for use on a later experiment. If you are new to column chromatography or just want a refresher, then read on for a quick…
Read MoreTroubleshooting Thin Layer Chromatography: Some TLC for Your TLC
The whole TLC technique sounds easy to do, but it can be difficult and tricky during interpretation or give unexpected results, especially when working with biomolecules. For this reason, it is important to be familiar with troubleshooting thin layer chromatography. Some of the common problems faced during TLC and their solutions are listed below: Solvent…
Read MoreHow to Choose Your MALDI (Soul) Matrix
gif by Kronin Okay not talking about that kind of matrix. But the kind of matrix that is crucial for MALDI (Matrix-Assisted Laser Desorption Ionization). I talked briefly about MALDI in my last article, Imaging Mass Spectrometry: The New(ish) Kid on the Block. Now I want to tell you more about MALDI, specifically the matrix.…
Read MoreHow to Measure Molecular Weight with Gel Permeation Chromatography (GPC)
So you have a new polymer, unknown protein, or material combination but don’t know its molecular weight? An easy way to measure molecular weight of your sample is gel permeation chromatography (GPC). GPC is an analytical technique that separates molecules in polymers by size and provides the molecular weight distribution of a material. GPC is…
Read MoreThin Layer Chromatography: The Basics
Like most other chromatographic techniques, thin layer chromatography (TLC) separates out individual compounds from a mixture depending upon the polarity of each compound. The solvent system travels up a silica plate by capillary action and passes over the sample that you spot onto the plate. As the solvent travels up, it moves the compounds present…
Read MoreThe Many Uses of Thin Layer Chromatography
While working as biologists, we often come across mixtures of compounds, and the first question that strikes our minds is ‘what are the components in this mixture?’ One might think of using chemical assays to find the presence of specific compounds. But that sounds painful, doesn’t it? Well, the good news is that thin layer…
Read MoreCarrying You Through Gas Chromatography
Maybe you found a paper in which they used gas chromatography (GC) to analyze a sample that is similar to yours and now you are wondering if you should try it too. If you are hesitant because you know little about GC, then this article will help you with that. You may already know that…
Read MoreWhat Can NMR Do For You – Part Three
Welcome to part three of “What Can NMR Do For You” This is an ongoing series in which we describe how you can use NMR experiments to characterize your protein of interest. In part one, we explained some critical points when doing one-dimensional (1D) NMR experiments on proteins and nucleic acids (e.g. sample preparation and…
Read MoreGetting the Most Out of Your Column: Optimizing Your HPLC Gradient
Let’s imagine the following scenario: You are researching a biosynthetic pathway in your favorite fungus. You know that this pathway produces a family of toxic compounds, and you want to see if you can block this pathway (or parts of it) with an antifungal drug. You have a control (no antifungal) and samples that have…
Read MoreHow You Can Use HPLC In Your Research
If you’re an HPLC guru, then you probably think that everyone should be using HPLC. And you might have a point – HPLC is very powerful and has broad applications across many fields. But it isn’t the answer to every problem. HPLC (high-performance liquid chromatography) is used to separate mixtures of compounds based on their…
Read MoreThe Seven Deadly Sins of HPLC
If you work with an HPLC, then you know the frustration of going to use the machine and finding it in disarray. If you’re new to using an HPLC, then the machine can be intimidating to use and you might not know the ins and outs of using it. Here’s an article that has a…
Read MoreRunning You Through HPLC: How Does it Work?
Your advisor tells you that he wants you to use HPLC to analyze your compound. You know that you’ve heard of this technique before, but you can’t remember what HPLC stands for, let alone how to go about doing it! We’ve all been there, though. Fear not! In this article, we will remind you about…
Read More