Altered distribution of transferrin isoforms according to serum storage conditions.

Establishment of stably ebv-transformed cell lines from residual clinical blood samples for use in performance evaluation and quality assurance in molecular genetic testing. al. Genetically characterized positive control cell lines derived from residual clinical blood samples.range (17.7 kb) allele-specific polymerase chain reaction method for direct haplotyping of R117H and IVS-8 mutations of the cystic fibrosis transmembrane regulator gene. detection of cystic fibrosis mutations in infertility patients with DNA sequence analysis. et al. Lung disease associated with the IVS8 5T allele of the CFTR gene. A candidate genetic risk factor for vascular disease: a common mutation in methylenetetrahydrofolate reductase. novel MHC class I-like gene is mutated in patients with hereditary haemo-haplotype-based molecular analysis of CFTR mutations associated with respiratory and pancreatic diseases. Rapid differentiation of five common [␣]-thalassemia genotypes by polymerase chain reaction. Measurements of carbohydrate-deficient transferrin (CDT) are used to detect alcohol abuse (1– 6). Various patient factors (7–11) and comigration of analytes with transferrin (Tf) isoforms (12, 13) can affect the results of the measurements. Recent studies have questioned the influence of serum and blood storage conditions on CDT and yielded varying (and sometimes contradictory) findings (14 –17). Moreover, the stability of CDT may vary among serum samples (14, 16). We studied CDT and Tf isoforms in serum specimens stored at 25 °C, 4 °C, and Ϫ20 °C. We used 100 discarded serum samples; 8 were from alcohol abusers in treatment (4 with increased disialo-Tf and the presence of asialo-Tf; 4 with increased disialo-Tf but without asialo-Tf), and 6 were from moderate drinkers (CDT within reference values). For sera from alcohol abusers, the alcohol abuse diagnosis was based on psychological evaluation; CDT, ␥-glutamyltransferase, and transaminase (aspartate ami-notransferase and alanine aminotransferase) concentrations ; and erythrocyte mean corpuscular volume. Each of the 14 specimens was divided into 3 samples and stored in glass vials (4 mL; Supelco 27137) at room temperature (25 °C in the dark), in a refrigerator (4 °C), or in a freezer (Ϫ20 °C). Samples were then analyzed periodically for 28 – 81 days [mean (SD), 51.6 (14.7) days]. The main reason for discontinuing follow-up was the appearance of solid particles in the serum. For frozen samples (Ϫ20 °C), the time between thawing and refreezing was Ͻ5 min. Serum Tf was analyzed (13) by use of capillary electrophoresis (P/ACE 5500) and a reagent set (CEofix; ANALIS). Elec-tropherograms displayed all major Tf isoforms: asialo-Tf (when present), disialo-Tf, trisialo-Tf, tetrasialo-Tf, …