Data in many biological problems are often compounded by imbalanced class distribution. That is, the positive examples may largely outnumbered by the negative examples. Many classification algorithms such as support vector machine (SVM) are sensitive to data with imbalanced class distribution, and result in a suboptimal classification. It is desirable to compensate the imbalance effect in model...

Molecular epidemiology uses biomarkers and advanced technology to refine the investigation of the relationship between environmental exposures and diseases in humans. It requires careful handling and storage of precious biological samples with the goals of obtaining a large amount of information from limited samples, and minimizing future research costs by use of banked samples. Many factors, s...

Agilent Captiva Premium PES syringe filters are evaluated and compared to other suppliers’ PES and PVDF syringe filters for the risk of losing protein during filtration. Captiva Premium PES syringe filters demonstrate low protein binding with excellent recovery for biological samples, especially for ‘sticky’ proteins at low concentrations. In addition, an assessment of filter extractables on LC...

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Agilent Captiva Premium PES syringe filters are evaluated and compared to other suppliers’ PES and PVDF syringe filters for the risk of losing protein during filtration. Captiva Premium PES syringe filters demonstrate low protein binding with excellent recovery for biological samples, especially for ‘sticky’ proteins at low concentrations. In addition, an assessment of filter extractables on LC...

Organic-aqueous liquid (phenol) extraction is one of many standard techniques to efficiently purify DNA directly from cells. With effective mixing, the cell components naturally distribute themselves into the two fluid phases in order to minimize interaction energies of the biological components with the surrounding solvents. The membrane and protein partition into the organic phase while the D...

We have developed a novel solid-phase extraction (SPE) system utilizing a temperature-responsive polymer hydrogel-modified stationary phase. Aminopropyl silica beads (average diameter, 40 - 64 μm) were coated with poly(N-isopropylacrylamide) (PNIPAAm)-based thermo-responsive hydrogels. Butyl methacrylate (BMA) and N,N-dimethylaminopropyl acrylamide (DMAPAAm) were used as the hydrophobic and cat...

Introduction Sample preparation is a critical step in scanning electron microscopy (SEM) imaging. This is especially true for biological samples because of charge build-up and sensitivity to vacuum and electron beam damage. In terms of ultrastructure imaging, a variety of advancements in detectors and approaches have improved biological imaging such that fewer steps are required for sample prep...

Since the late 1980s, atomic force microscopy (AFM) has been increasingly used in biological sciences and it is now established as a versatile tool to address the structure, properties and functions of biological specimens. AFM is unique in that it provides three-dimensional images of biological structures, including biomolecules, lipid films, 2D protein crystals and cells, under physiological ...