Mikromethode zur Bestimmung von N-Acetyl-Neuraminsäure in Glykoproteinen

Abstract

Zusammenfassung: Es wird eine Mikromethode zur Bestimmung freier bzw. gebundener N-Acetyl-Neuraminsäure (NANA) in Glykoproteinen auf der Grundlage der Periodatoxidation und Thiobarbituratreaktion beschrieben. Die Methode zeichnet sich durch einfache Durchführbarkeit bei Verwendung des Mikrolitersystems Eppendorf aus. Die Nachweisempfindlichkeit liegt bei 0,2 nmol NANA im Testansatz. Die Präzision in der Serie beträgt 3,0%, die Langzeitpräzision 4,3% (VK). Die Richtigkeit der erhaltenen Ergebnisse wurde durch Vergleichsuntersuchungen mit der Makromethode nach Warren ((1959), J. Biol. Chem. 234, 1971Chem. 234, -1979 an Referenzmaterial (Sialyllactose, Transferrin, Fibrinogen) unter Beweis gestellt. A micromethod for the determination ofN-acetylneuraminic acid in glycoproteinsSummary: A micromethod is described for the determination of free or glycoprotein-bound N-acetylneuraminic acid ( ) on the basis of oxidation with periodic acid and reaction with thiobarbiturate. When using the Eppendorf microliter system the method is easy to perform, the lowest level of sensitivity being 0.2 nmoles NANA in the incubation mixture. The intraassay precision comprises 3.0% CV, the interassay precision 4.3% CV. The accuracy of the results obtained by this micromethod was proved by comparative experiments with the macromethod according to Warren ((1959), J. Biol. Chem. 234, 1971 using sialyllactose, transferrin and fibrinogen as reference materials. Einführung

Sialic Acid in Human Serum and Cerebrospinal Fluid. Comparison of methods and reference values

“…Silver et al (22) described CVs of 2.1% (intraassay) and 5.2% (interassay) for the entire procedure. These figures agreed better with data reported for the chemical microassay (3.0% intraassay, 4.3% interassay (18)) and the enzymatic test (1.0% intraassay, 1.9% interassay (19)) than with resülts published for Warren 9 s method (1.9% within-run, 10% day-to-day (22)). These figures agreed better with data reported for the chemical microassay (3.0% intraassay, 4.3% interassay (18)) and the enzymatic test (1.0% intraassay, 1.9% interassay (19)) than with resülts published for Warren 9 s method (1.9% within-run, 10% day-to-day (22)).…”

“…The analytical r nge was identical to the linear response of the original procedure (18). 1), which evidently improved the sensitivity of the method (tab.…”

“…For this study we excluded sera with following.criteria: -glucose above 6.4 mmol/1 (fasting) or above 8.0 mmol/1 (postprandial) estimated by the glucose dehydrogenase method (11), -creatinine above 110 μπιοΐ/ΐ (males) and above 90 μπιοΐ/ΐ (females) measured with alkaline picrate (12) by a kinetic method (13), and -γ-glutamyltransferase above 28 U/l (males) and above 18 U/l (females) assayed with L-y-glutamyl-3-carboxy-4-nitroanilide at 25 °C (14). High performance liquid chromatography (HPLC) was performed with Kontron Instruments.…”

The effects of phenytoin dosage on the induction of α1-acid glycoprotein and antipyrine clearance in the dog

“…Antipyrine kinetics were measured twice weekly for the next three weeks and samples of blood for AGP assay were obtained twice weekly for four weeks. oc I-Acid glycoprotein was assayed by combining parts of two other assays for AGP (14,15). The details of our assay were reported earlier (8).…”