Thin-layer chromatography

About: Thin-layer chromatography is a research topic. Over the lifetime, 7494 publications have been published within this topic receiving 124179 citations. The topic is also known as: TLC.

Isolation of bacterial DNA from soil.

Abstract: DNA has been isolated from the bacterial fraction of two soils. Numbers of bacteria, determined by fluorescence microscopy were 1.1 and 2.2·10 10 cells g −1 dry wt. The total amounts of bacterial DNA in these soils were 90 and 187 μg g −1 dry wt respectively. A modification of Marmur's method was used to isolate DNA, but difficulties in separating DNA from humic substances gave low yields and impure DNA. DNA could be partly separated from humic material in the presence of 8 m urea by ion-exchange chromatography on DEAE-Sepharose CL-6B. Final purification was obtained by chromatography on a hydroxyapatite column. When lowering the EDTA concentration in the saline-EDTA solution used for lysis, the amount of humic substances in the cell-free lysate after centrifugation was considerably decreased. The lysate could then be chromatographed directly on hydroxyapatite. Quantities up to 1.5 mg DNA high purity was isolated from 90 g wet soil (37 g dry wt). The isolated DNA was characterized by treatment with DNAse and absorption spectra. No uncommon bases were revealed by thin layer chromatography of the DNA hydrolysates. Melting curves of the isolated DNA showed a relatively broad melting profile, with half maximum hyperchromicity (T m ) near 90°C. Sedimentation coefficients determined by analytical ultracentrifugation showed that the isolated DNA had a high molecular weight, ranging from 2.3 to 10.1·10 5 daltons.

Familial giant cell hepatitis associated with synthesis of 3 beta, 7 alpha-dihydroxy-and 3 beta,7 alpha, 12 alpha-trihydroxy-5-cholenoic acids.

Abstract: Urinary bile acids from a 3-mo-old boy with cholestatic jaundice were analyzed by ion exchange chromatography and gas chromatography-mass spectrometry (GC-MS). This suggested the presence of labile sulfated cholenoic acids with an allylic hydroxyl group, a conclusion supported by analysis using fast atom bombardment mass spectrometry (FAB-MS). The compounds detected by FAB-MS were separated by thin layer chromatography and high performance liquid chromatography. The sulfated bile acids could be solvolyzed in acidified tetrahydrofuran, and glycine conjugates were partially hydrolyzed by cholylglycine hydrolase. Following solvolysis, deconjugation, and methylation with diazomethane, the bile acids were identified by GC-MS of trimethylsilyl derivatives. The major bile acids in the urine were 3 beta,7 alpha-dihydroxy-5-cholenoic acid 3-sulfate, 3 beta,7 alpha,12 alpha-trihydroxy-5-cholenoic acid monosulfate, and their glycine conjugates. Chenodeoxycholic acid and cholic acid were undetectable in urine and plasma. The family pedigree suggested that abnormal bile acid synthesis was an autosomal recessive condition leading to cirrhosis in early childhood.

The quantitative analysis of triglyceride mixtures by thin layer chromatography on silica impregnated with silver nitrate

Abstract: The paper describes a procedure involving thin layer chromatography on silica impregnated with silver nitrate, which makes possible the separation of synthetic and natural glyceride mixtures into classes according to their degree of unsaturation, and within those classes the resolution of certain isomeric unsaturated glycerides. The separations depend upon the ability of compounds having an olefinic double bond to form co-ordination complexes with the silver ion.

Separation and purification of anthocyanins by high-speed countercurrent chromatography and screening for antioxidant activity.

Abstract: The all-liquid chromatographic technique of high-speed countercurrent chromatography (HSCCC) has been applied for separations of anthocyanins. The biphasic mixture of tert-butyl methyl ether/n-butanol/acetonitrile/water (2:2:1:5) acidified with trifluoroacetic acid was found to be a suitable solvent system for anthocyanin separation. In some cases, enrichment of the pigments on Amberlite XAD-7 resin prior to HSCCC has been carried out. The anthocyanin mixtures from red cabbage, black currant, black chokeberry, and roselle were successfully fractionated using HSCCC. Peak purity control was done by nuclear magnetic resonance spectroscopy as well as electrospray ionization ion trap multiple mass spectrometry. Finally, antioxidant activity of the purified pigments was determined using the Trolox equivalent antioxidant capacity test.