Simple method to determine the concentration and incorporation ratio of ruthenium-labeled antibodies

Aim: Ruthenium-labeled antibodies are commonly used detection reagents in bioanalysis assays and must be characterized to ensure quality. The aim of this work was to develop a method to determine the concentration and incorporation ratio (the degree of labeling [DOL]) of ruthenium-labeled antibodies by UV/VIS spectroscopy. Materials & methods: Free SULFO-TAG compound was scanned using UV/VIS and showed an absorbance peak at 292 nm. In contrast, antibodies demonstrate UV absorbance at 280 nm. After experimentally determining the extinction coefficients at 280 and 292 nm of free ruthenium and antibody, we generated a formula based on the Beer–Lambert law that calculates both concentration and DOL of these ruthenium-labeled antibodies. Conclusion: The concentration and DOL values determined by our method were comparable to those determined from bicinchoninic acid and LC/MS for the same reagents. This method creates a faster and more accessible reagent characterization process that uses far less reagent than the more traditional alternatives.

The impact of ligand binding based assays critical reagent characterization and storage

Biological critical reagents are the foundation of many bioanalytical methods and often chemically modified or conjugated with various chemical tags. As such, the quality and performance of these methods are inherently tied to the quality and stability of critical reagents. This article will outline recommendations for conjugated critical reagent development and characterization. Examples of the impact of regent quality will be discussed for the two common bioanalytical assays in support of drug development for biotherapeutics. Finally, a brief discussion of conjugated reagent stability and recommendations for storage and testing will be presented.

SINTESIS KOMPOSIT SELULOSA SERBUK GERGAJI KAYU KAMPER-LIMBAH PLASTIK LDPE (LOW DENSITY POLIETHYLENE) DENGAN REAGEN FENTON SEBAGAI AGEN PENGKOPLING

This research was on the synthesis of cellulose composites from camphor wood sawdust with LDPE waste (cellulose-LDPE) and Fenton reagent (H2O2/Fe2+) as the coupling agent. This study was divided into three steps: preparation, variation of LDPE composition and H2O2 concentration, and characterization. Preparation was done with cellulose extraction of sawdust and LDPE plastic waste purification. Variation was performed to determine the effect of compositions of LDPE on composites celullose-LDPE and H2O2 concentration on Fenton reagent. Characterization was done by testing the physical properties and functional groups using FTIR analysis. The best values of the physical property were obtained from cellulose-LDPE composition ratio of 1:5 on 1.5% H2O2. These were MOE (Modulus of Elasticity) of 12.71 MPa, MOR (Modulus of Rupture) of 200.24 MPa and density of 0.7936 g/cm. FTIR analysis showed the higher the composition of LDPE, the higher the wavenumber for OH and the increase of H2O2 concentration increased the C-H wavenumber functional groups.