L(+)-Aspartic acid, Millipore®

Supplier: Merck

Soluble in water and mineral acids; insoluble in organic solvents.

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HPLC columns, Chromolith® DIOL

Supplier: Merck

Chromolith® DIOL columns are useful as an intermediate polarity media between C18 and silica. Diol functionalised media is less polar and can have different selectivity. Chromolith® DIOL can be used with a wide range of solvents in both normal and reverse phases. In normal phase mode, the diol phase provides an alternative selectivity compared to silica whilst additionally demonstrating longer retention times that help to obtain separation. In reverse phase mode, compounds such as water-soluble vitamins, sugars or amino acids are easily baseline separated using simple mobile phases. Chromolith® DIOL columns have long lifetimes within pH range of 2,5 to 7,5, high matrix tolerance and speed of analysis.

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LC-SPDP (Succinimidyl 6-[3-(2-pyridylthio)propionamidohexanoate) ≥95%, Sigma-Aldrich®

Supplier: Merck

The amine-reactive portion of SPDP reagents is the N-hydroxysuccinimide (NHS) ester. Reactions are most commonly performed in phosphate, carbonate/bicarbonate, or borate buffers at pH 7-8. Other buffers can be used provided they do not contain primary amines (or thiols or disulfide reducing reagents – see discussion of the sulfhydryl reactivity). The rate of reaction and degradation by hydrolysis increases with increasing pH; for example, the half-life of the NHS ester is several hours at pH 7 and less than 10 minutes at pH 9. NHS-ester reagents like SPDP and LC-SPDP have limited aqueous solubility and must be dissolved in organic solvent before adding them to a reaction mixture. Sulfo-NHS-ester reagents like Sulfo-LC-SPDP are water-soluble and can be added directly to aqueous reaction mixtures.

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Sulpho-EGS (Ethylene glycol bis(sulphosuccinimidyl succinate)), Sigma-Aldrich®

Supplier: Merck

EGS is a water-insoluble, homobifunctional N-hydroxysuccinimide ester (NHS ester) and Sulfo-EGS is its water-soluble analog. The spacer arm contains two cleavable ester sites that may be broken with hydroxylamine, which yields two fragments with terminal amide bonds and the release of ethylene glycol. These reagents are often used for conjugating radiolabeled ligands to cell surface receptors. The water insoluble reagent EGS does not possess a charged group, is lipophilic and, therefore, membrane-permeable and useful for intracellular and intramembrane protein conjugation. EGS is first dissolved in DMSO or DMF and added to the aqueous reaction mixture at a final solvent concentration of 10-20%, to minimize detrimental affects to the protein.

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L(+)-Glutamic acid, Millipore®

Supplier: Merck

Soluble in water and mineral acids; insoluble in organic solvents. In aqueous solutions forms pyrrolidonecarboxylic acid slowly at room temperature, more rapidly at 100 °C.

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Supelco® TraceCERT® Organic Reference Standard, Simazine

Supplier: Merck

Simazine CRM may also be used as given below: Development and validation of an ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME) method for sample extraction followed by gas chromatography-mass spectrometry based determination of endocrine-disrupting herbicides in the river and seawater samples. Determination of triazine pesticide residues in samples of apples pears carrots potatoes tomatoes avocado cucumber spinach bananas and oranges by modified QuEChERS and solid-phase extraction (SPE) procedures followed by liquid chromatography-photodiode array (LC-DAD) analysis. Multi-residue analysis of 67 pesticides in olive oil olives and avocado samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to evaluate various clean-up sorbents. Quantitation of 20 pesticides in eel and shrimp samples by a scheduled multiple reaction monitoring (sMRM) method and QuEChERS with EDTA for sample extraction and purification. Analysis of 35 micropollutants including pesticides in water samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after their solid-phase extraction. Simultaneous quantification of 58 pharmaceuticals and personal care products (PPCPs) and pesticides in water samples by solvent-based de-emulsification dispersive liquid-liquid microextraction (SD-DLLME) combined with liquid chromatography-tandem mass spectrometry (LCMS/MS).

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Xylene substitute, Neo-Clear®, Sigma-Aldrich®

Supplier: Merck

Neo-Clear® is a non hazardous alternative to xylene. It is virtually odourless, compatible with most high purity solvents and is characterised by lower evaporation rates than xylene, making it a lower health risk.

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Water-free mounting medium, Neo-Mount®

Supplier: Merck

Water-free mounting media, such as Neo-Mount®, should be used for permanent mounting and long-term storage of samples. Slides processed in pathologyl laboratories need to be stored up to 10 years, whereby the staining results need to be stable and fading-out is not acceptable. Neo-Mount®, anhydrous mounting medium for microscopy is an extremely colour-stable mounting medium for microscopy, which is produced with solvents based on mixtures of aliphatic hydrocarbons. It contains an aromatic-free substitute for xylene, thus, Neo-Mount® needs to be combined with Neo-Clear® exclusively. Xylene must be avoided in the mounting step, as it will cause the slides to become cloudy and streaked. In addition, by placing the dehydrated slides on filter paper for approx. 1 minute prior to mounting, any excess Neo-Clear® should be circumvented, as air bubbles might arise under the cover slip. The same pre-condition should also be met when mounting specimens using cover slip machines; in this area, Neo-Clear® can be most efficiently eliminated by incubating the slides for 1 minute in an empty slide rack.