[Studies on the accuracy and precision of total serum cholesterol in regional interlaboratory trials (author's transl)].

The between-run precision of the Liebermann-Burchard reaction modified by Watson was, in our laboratory, 2-3%, the within-run coefficient of variation was 1-2%. The between-run precision of the enzymatic test was 3-4%, the within-run coefficient of variation was 3%. The regression analysis of 92 serum specimens from patients was y = -17.

Effect of polyamines on the uptake of poly (2'-fluoro-2'-deoxyuridylic acid) by a mammalian cell line.

VERO cells can take up poly(dUfl)1 from the medium. The uptake involves surface adsorption and, most probably, intracellular penetration. Part of the poly(dUfl) is hydrolyzed during incubation with the cells but the hydrolysis products are not incorporated into de novo synthesized nucleic acids.

[Blood-sugar determination with the Reflomat (author's transl)].

A total of 710 blood samples was tested with the new Reflomat apparatus. There was a good correlation with the GOD-Perid method (correlation coefficient for serum r = 0.993; for whole blood r = 0.

Polarography of polynucleotides. 3. Polyadenylic acid: the electrode process and interaction with polyamines.

Polyadenylic acid (poly A) was studied under various conditions using both DC polarography and phase sensitive AC polarography and by measuring the time-course of the current during the lifetime of a single drop of the dropping mercury electrode. Under certain conditions the current at potentials of the limiting portion of the DC polarographic wave does not reach its limiting value and in extreme situations peak-shaped curves are observed. This phenomenon is explained in terms of desorption and repulsion from the electrode of neutral poly A due to its polyanionic character.