A Novel Analysis Method for Lactate Dehydrogenase Activity in Serum Samples Based on Fluorescence Capillary Analysis

Abstract

Based on fluorescence capillary analysis technology, a method for quantitating lactate dehydrogenase (LDH) activity in a micro-volume sample was developed. Sample and reagent consumptions were merely 2 and 16 μL per time, respectively. The optimized test conditions were as follows. The reaction reagent consisted of 0.10 M phosphate buffer (pH 6.5), 0.30 mM NADH and 1.20 mM pyruvate. NADH standard was prepared with a phosphate buffer of pH 8.0, and its linear response was controlled in 0.05 -0.30 mM. LDH standards containing 2.0 mM PEG could exhibit long-term stability. Under the optimized conditions, a linear response for LDH from 50 to 1200 U L -1 and a detection limit of 31 U L -1 were obtained with good precision (RSD: 2.1 -2.2%, n = 10) and better recovery of 96 -105%. The method's characteristics was high sensitivity, low consumptions, simple operations, good precision and reliability, lending itself to the miniaturization of fluorophotometer which transformed into a bedside instrument in the hospital.

Serum lactate dehydrogenase activities as systems biomarkers for 48 types of human diseases

“…One is monitoring the NAD+ absorbance reduction at 340 nm. The other is a kinetic determination for LDH activity level based on the oxidation rate of NADH 34 . In addition, based on fluorescent NADH to non-fluorescent NAD+, fluorescent capillary analysis technology (FCA) is used to determine LDH activity level 34 .…”

A highly selective and sensitive fluorescent probe for lactate dehydrogenase based on ultrabright adenosine monophosphate capped gold nanoclusters

“…S4B †), illustrating the possibility to detect trace amounts of rLDH at the present condition. Such a LOD was more sensitive than the reported ones by using molecular beacon DNA molecule, 21 porous silicon microcavities, 22 pyruvate and NADH as substrate, 23 CdTe/CdS QDs 24 and so on (Table S1 †). Yang et al had explored a highly selective uorescent probe for LDH based on CdTe quantum dots, where the linear calibration plots of the activity of LDH were obtained from 250 to 6000 U L À1 .…”