scholarly journals Enzyme-linked oligonucleotide hybridization assay for direct oligo measurement in blood

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Mary Y Lorenson ◽  
Kuan-Hui Ethan Chen ◽  
Ameae M Walker
Keyword(s):  
Biological Fluids ◽  
Solid Substrate ◽  
Cell Uptake ◽  
Hybridization Assay ◽  
Sample Handling ◽  
Oligonucleotide Hybridization ◽  
Plate Reader ◽  
Reaction Amplification ◽  
Covalently Linked ◽  
Polymerization Chain

Abstract Small oligonucleotides (oligos) are increasingly being utilized as diagnostics or treatments for disease. An impediment to broader use is the ability to readily measure oligos in biological fluids. Here, we describe a very straightforward assay with detection in the sub-picomole range that does not require extraction from serum/plasma or polymerization chain reaction amplification. As a result, there are no losses or errors due to sample handling, and the assay can be used to measure oligos modified in a variety of ways that increase therapeutic efficacy. The enzyme-linked oligonucleotide hybridization assay (ELOHA) is based on competition with a detection oligo for hybridization to a capture oligo covalently linked to a solid substrate. The versatility of ELOHAs is demonstrated by application to the measurement of three oligos, including two morpholino-oligos with 3′-octaguanidine derivatization for efficient cell uptake. The third oligo is unmodified and has a DNA sequence equivalent to miR93. The assays have sensitivity as low as 0.28 pmol/sample reaction at 50% hybridization. Adding to clinical utility is the need for only a simple 96-well absorbance plate reader and the finding that neither EDTA nor heparin interferes with detection.

scholarly journals Standardization of Clinical Cholinesterase Measurements

2002 ◽  
Vol 21 (5) ◽  
pp. 385-388 ◽  
Author(s):  
Barry W. Wilson ◽  
John D. Henderson ◽  
Al Ramirez ◽  
Michael A. O'Malley
Keyword(s):  
East Coast ◽  
Worker Safety ◽  
University Of California ◽  
Poor Correlation ◽  
Acetyl Cholinesterase ◽  
Blood Samples ◽  
Sample Handling ◽  
Clinical Laboratories ◽  
Plate Reader ◽  
Assay Methods

Previous studies showed that commonly used kits for measuring cholinesterases were not optimal for determining acetyl-cholinesterase (ACh E) activity. Clinical use of different kits and methodologies resulted in ACh E levels being reported in different units and activities that were not reproducible among laboratories. Findings such as these led to a revision in California regulations (covering ACh E measurements for pesticide worker safety) calling for clinical laboratories to standardize their findings. The laboratories were contacted and invited to participate in a split-sample study of human blood ACh E and nonspecific cholinesterase (BCh E) assays. Participating laboratories measured erythrocyte (RBC) ACh E and/or plasma BCh E from undiluted and 50% diluted blood, according to their practices. Aliquots of blood samples were shipped to University of California Davis for measurement, using an optimized semiautomated plate reader version of the method of Ellman. Nine of 25 laboratories sent samples for comparison. Two others performed their own comparisons and submitted data to the state. Best correlations were obtained with BCh E activity. Correlations ( r2) were.88 or above for four of five laboratories for BCh E, and above.9 for two of seven laboratories for ACh E. Reasons for poor correlations may include difficulties in pipetting RBCs, storage, and processing. A bovine ACh E RBC ghost “standard” was devised and tested. Activity of the preparation was maintained at-70°C for approximately 11 months. A test with an East coast laboratory resulted in a high correlation, demonstrating the reliability of the RBC ghost standard and that one laboratory can replicate the ACh E findings of another. The overall poor correlation of interlaboratory cholinesterase results points to the need to further standardize sample handling and assay methods.

Determination of aluminum in biological samples by atomic absorption spectrophotometry with a graphite furnace.

1978 ◽  
Vol 24 (9) ◽  
pp. 1485-1490 ◽  
Author(s):  
J E Gorsky ◽  
A A Dietz
Keyword(s):  
Atomic Absorption ◽  
Biological Fluids ◽  
Graphite Furnace ◽  
Atomic Absorption Spectrophotometry ◽  
Graphite Tube ◽  
Sample Handling ◽  
Absorption Spectrophotometry ◽  
Precision And Accuracy ◽  
The Brain

Abstract Aluminum, generally considered non-essential and non-toxic, may accumulate in toxic amounts in the brain in cases of chronic renal failure. We describe a procedure for its analysis in biological fluids by atomic absorption spectrophotometry with a graphite furnace. No sample preparation is required and the procedure is sensitive at the appropriate concentrations. A sample of serum or urine is pipetted into the interior of the graphite tube, where it is sequentially dried, charred, and atomized. Precautions for sample handling are discussed and instrument settings are defined. Precision and accuracy of the method are evaluated, as are the effects of salts, protein content of serum, and specific gravity of urine. Serum of 23 persons who were not consuming aluminum-containing antacids contained 28 +/- 9 (SD) microgram of Al per liter (1.02 +/- 0.33 mumol/liter).

Application of Inductively-Coupled Plasma Excitation Sources to the Determination of Trace Metals in Microliter Volumes of Biological Fluids

1973 ◽  
Vol 19 (8) ◽  
pp. 807-812 ◽  
Author(s):  
Richard N Kniseley ◽  
Velmer A Fassel ◽  
Constance C Butler
Keyword(s):  
Inductively Coupled Plasma ◽  
Biological Fluids ◽  
Spectroscopic Technique ◽  
Direct Reading ◽  
Sample Handling ◽  
Inductively Coupled ◽  
Multielement Determination ◽  
Plasma Excitation ◽  
Trace Constituents

Abstract The inductively coupled plasma is a promising excitation source for the simultaneous multielement determination of trace (nanogram per milliliter) elements in biological fluids. As little as 25 µl of sample fluid (whole blood, serum, or plasma) has been used, with essentially no sample preparation. This technique offers significant advantages over other methods requiring considerable sample handling that may greatly increase the danger of contamination or loss of trace constituents. The precision of the method is typically ±3 to 5%. Because this is an emission spectroscopic technique, a multichannel direct-reading spectrometer allows simultaneous multielement analyses to be made on microliter samples.

scholarly journals Challenges for Biomarker Discovery in Body Fluids Using SELDI-TOF-MS

2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
Muriel De Bock ◽  
Dominique de Seny ◽  
Marie-Alice Meuwis ◽  
Jean-Paul Chapelle ◽  
Edouard Louis ◽  
...  
Keyword(s):  
Biomarker Discovery ◽  
Biological Fluids ◽  
Protein Profiling ◽  
Sample Collection ◽  
Sample Handling ◽  
Biomarker Identification ◽  
The Past ◽  
Set Up ◽  
And Storage ◽  
Tof Ms

Protein profiling using SELDI-TOF-MS has gained over the past few years an increasing interest in the field of biomarker discovery. The technology presents great potential if some parameters, such as sample handling, SELDI settings, and data analysis, are strictly controlled. Practical considerations to set up a robust and sensitive strategy for biomarker discovery are presented. This paper also reviews biological fluids generally available including a description of their peculiar properties and the preanalytical challenges inherent to sample collection and storage. Finally, some new insights for biomarker identification and validation challenges are provided.

scholarly journals EPCT-25. SMO PROTEIN DEPLETION IN SHH MEDULLOBLASTOMAS USING MICROBUBBLE-ENHANCED ULTRASOUND AND SIRNA LOADED CATIONIC NANOPARTICLES

2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i52-i52
Author(s):  
Yutong Guo ◽  
Hohyun Lee ◽  
Zhou Fang ◽  
Anastasia Velalopoulou ◽  
Jinhwan Kim ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Biological Fluids ◽  
Cationic Lipid ◽  
Physical Method ◽  
Cell Uptake ◽  
Hybrid Nanoparticles ◽  
Direct Result ◽  
Systemic Delivery ◽  
Protein Depletion

Abstract RNA-based therapies offer unique advantages for treating pediatric brain tumors. However, the systemic delivery remains a major problem due to degradation of unmodified RNA in biological fluids, poor brain accumulation, and poor cancer cell uptake or escape from the endosomal lipid bilayer barrier. While nanoparticle encapsulation can prolong circulation time and facilitate cellular uptake, their accumulation in brain tumor remains particularly poor due to their low permeability across the blood-brain barrier and limited intratumoral penetration. Focused ultrasound, when combined with circulating microbubbles (MB-FUS) provides a physical method to transiently modulate the brain tumor microenvironment (TME) and improve nanoparticle delivery. Here, we have examined the delivery of siRNA targeting the Smoothened (SMO) pathway, packaged in 50 nm cationic lipid-polymer hybrid nanoparticles (cLPH:siRNA-SMO), combined with MB-FUS in murine SmoA2 sonic hedgehog (SHH) medulloblastoma. At 30 hours after treatment, we observed the depletion of the SMO protein target, responsible for driving SHH medulloblastoma formation and growth, in mice that had received treatment with MB-FUS and cLPH:siRNA-SMO, but not with cLPH:siRNA-SMO alone. We also confirmed that SMO protein depletion was spatially achieved in the tumor regions with detected cLPH:siRNA-SMO using FISH assay, and that there was 15 fold induction of tumor cell apoptosis compared to tumors in mice that had received cLPH:siRNA-SMO alone. The limited induction of apoptosis was observed with either cLPH:siRNA (non-targeting) or MB-FUS and cLPH:siRNA (non-targeting), suggest that the observed apoptosis induction in the SmoA2 model was the direct result of SMO depletion rather than nonspecific effects of MB-FUS or cLPH:siRNA. Our findings provide a paradigm shift in drug delivery in brain tumors, where physical methods and nanotechnology are tuned together to develop rational strategies for the effective delivery of nucleic acids in brain tumors.

scholarly journals Heterogeneous oligonucleotide-hybridization assay based on hot electron-induced electrochemiluminescence of a rhodamine label at oxide-coated aluminum and silicon electrodes

2006 ◽  
Vol 51 (25) ◽  
pp. 5438-5444 ◽  
Author(s):  
Anna-Maria Spehar-Deleze ◽  
Johanna Suomi ◽  
Qinghong Jiang ◽  
Nico de Rooij ◽  
Milena Koudelka-Hep ◽  
...  
Keyword(s):  
Hybridization Assay ◽  
Hot Electron ◽  
Oligonucleotide Hybridization

scholarly journals Wall-induced translation of a rotating particle in a shear-thinning fluid

2021 ◽  
Vol 927 ◽  
Author(s):  
Ye Chen ◽  
Ebru Demir ◽  
Wei Gao ◽  
Y.-N. Young ◽  
On Shun Pak
Keyword(s):  
Biomedical Applications ◽  
Physical Mechanism ◽  
Complex Fluids ◽  
Biological Fluids ◽  
Shear Thinning ◽  
Solid Substrate ◽  
The Impact ◽  
Direction Opposite ◽  
Shear Thinning Fluid ◽  
Wall Interactions

Particle–wall interactions have broad biological and technological applications. In particular, some artificial microswimmers capitalize on their translation–rotation coupling near a wall to generate directed propulsion. Emerging biomedical applications of these microswimmers in complex biological fluids prompt questions on the impact of non-Newtonian rheology on their propulsion. In this work, we report some intriguing effects of shear-thinning rheology, a ubiquitous non-Newtonian behaviour of biological fluids, on the translation–rotation coupling of a particle near a wall. One particularly interesting feature revealed here is that the wall-induced translation by rotation can occur in a direction opposite to what might be intuitively expected for an object rolling on a solid substrate. We elucidate the underlying physical mechanism and discuss its implications on the design of micromachines and bacterial motion near walls in complex fluids.

Novel biomarker and drug delivery systems for theranostics – extracellular vesicles

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ewa Ł. Stępień ◽  
Carina Rząca ◽  
Paweł Moskal
Keyword(s):  
Drug Delivery ◽  
Extracellular Vesicles ◽  
Drug Delivery Systems ◽  
Biological Fluids ◽  
Cell Types ◽  
Biological Properties ◽  
Delivery Systems ◽  
Cell Uptake ◽  
Positron Emission ◽  
Composition Structure

Abstract Extracellular vesicles (EVs) are nano- and micro-sized double-layered membrane entities derived from most cell types and released into biological fluids. Biological properties (cell-uptake, biocompatibility), and chemical (composition, structure) or physical (size, density) characteristics make EVs a good candidate for drug delivery systems (DDS). Recent advances in the field of EVs (e.g., scaling-up production, purification) and developments of new imaging methods (total-body positron emission tomography [PET]) revealed benefits of radiolabeled EVs in diagnostic and interventional medicine as a potential DDs in theranostics.

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