This paper describes a novel two-site peptide immunoassay using the isotope 14C as the label and accelerator mass spectrometry as the detection system. A mouse monoclonal antibody (1A5) against the amino terminal region of human parathyroid hormone-related protein (PTHrP) was labeled with 14C by growing the hybridoma cells in a miniPERM bioreactor in the presence of [U-14C]L-leucine and [U-14C]...

14C is one of the limiting radionuclides used in the categorization of radioactive graphite waste; this categorization is crucial in selecting the appropriate graphite treatment/disposal method. We propose a rapid analysis method for 14C specific activity determination in small graphite samples in the 1-100 μg range. The method applies an oxidation procedure to the sample, which extracts 14C fr...

Bottromycin A2 inhibited MS2 phage RNA-dependent protein synthesis as well as polyuridylic acid-(poly(U))- or polyadenylic acid (poly(A))-dependent polypeptide synthesis. When the ribosomal complex with N-acetyl-[14C]phenylalanyl-tRNA (N-acetyl-[14C]Phe-tRNA) at the A site was subjected to bottromycin A2, the release of N-acetyl-[14C]Phe-tRNA was observed while no release of N-acetyl-[14C]Phe-t...

A definite contribution of the glucuronic acid pathway to total glucose metabolism by rat adipose tissue in vitro in the presence of growth hormone preparations has not been found. Randomization of 14C of glucose-5-14C into glycerol and glucose-l-14C and -2-14C into glycogen on incubation of rat epididymal tissue indicates that the pathway contributes at most only a few per cent to the over-all...

Identifying drivers of seasonal variations in fluvial particulate organic carbon (POC) composition can aid sediment provenance and biogeochemical cycling studies. We evaluate changes POC the Río Bermejo, Argentina, a lowland river running ?1,270 km without tributaries. Weekly concentration isotopic from 2016 to 2018 show that during wet season, increased lateral channel migration generates an i...

Microsomal membrane preparations from the developing endosperm of castor bean (Ricinus communis) catalysed the transfer of oleate from [14C]oleoyl-CoA to phosphatidylcholine (PtdCho). In the presence of NADH, radioactive ricinoleate (12-hydroxyoctadec-9-enoate) was synthesized from [14C]oleate, and this was largely recovered in PtdCho and as free fatty acid. The addition of unlabelled ricinoleo...

The pathways of glycogen synthesis from glucose were studied using double-isotope procedures in 18-day cultured foetal-rat hepatocytes in which glycogenesis is strongly stimulated by insulin. When the medium containing 4 mM-glucose was supplemented with [2-3H,U-14C]glucose or [3-3H,U-14C]glucose, the ratios of 3H/14C in glycogen relative to that in glucose were 0.23 +/- 0.04 (n = 6) and 0.63 +/...

A preferential incorporation of dietary arachidonic acid (20:4, n-6) into chyle lipoprotein phospholipids, a relative resistance of 20:4 esters of chyle triacylglycerol (TG) to hydrolysis by lipoprotein lipase, a preferential utilization of 20:4 for phospholipid acylation, and a low rate of oxidation of 20:4 are factors that may contribute to the differences seen in the incorporation into tissu...