| 1. |
- Ahnoff, Martin, et al.
(författare)
-
Matrix effect explained by unexpected formation of peptide in acidified plasma
- 2015
-
Ingår i: Bioanalysis. - : Future Science Ltd. - 1757-6180 .- 1757-6199. ; 7:3, s. 295-306
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: Peak distortion and strong signal enhancement was observed when applying a bioanalytical method based on mixed-mode SPE, hydrophilic interaction chromatography and ESI-MS to acidified rabbit plasma samples. Results: High-resolution ESI-MS and N-terminal peptide sequencing revealed a peptide NFQNAL, which was confirmed by H/D exchange ESI-MS. Conclusion: The peptide causing the observed matrix effect was formed by enzymatic degradation of serum albumin at pH 3. Degradation required both acidification and presence of other plasma constituents in addition to albumin to take place. The degree of signal enhancement correlated to the level of NFQNAL in the ion source as measured by MS, with a maximal enhancement factor of 3 at intermediate levels of NFQNAL. The interference was eliminated by changing to another type of hydrophilic interaction chromatography column.
|
|
| 2. |
- Ahnoff, Martin, et al.
(författare)
-
Thermal inactivation of enzymes and pathogens in biosamples for MS analysis
- 2015
-
Ingår i: Bioanalysis. - : Future Science Ltd. - 1757-6180 .- 1757-6199. ; 7:15, s. 1885-1899
-
Tidskriftsartikel (refereegranskat)abstract
- Protein denaturation is the common basis for enzyme inactivation and inactivation of pathogens, necessary for preservation and safe handling of biosamples for downstream analysis. While heat-stabilization technology has been used in proteomic and peptidomic research since its introduction in 2009, the advantages of using the technique for simultaneous pathogen inactivation have only recently been addressed. The time required for enzyme inactivation by heat (approximate to 1 min) is short compared with chemical treatments, and inactivation is irreversible in contrast to freezing. Heat stabilization thus facilitates mass spectrometric studies of biomolecules with a fast conversion rate, and expands the chemical space of potential biomarkers to include more short-lived entities, such as phosphorylated proteins, in tissue samples as well as whole-blood (dried blood sample) samples.
|
|
| 3. |
- Ashri, Nadia Y., et al.
(författare)
-
Sample treatment based on extraction techniques in biological matrices
- 2011
-
Ingår i: Bioanalysis. - 1757-6180 .- 1757-6199. ; 3:17, s. 2003-2018
-
Forskningsöversikt (refereegranskat)abstract
- The importance of sample preparation methods as the first stage in bioanalysis is described. In this article, the sample preparation concept and strategies will be discussed, along with the requirements for good sample preparation. The most widely used sample preparation methods in the pharmaceutical industry are presented; for example, the need for same-day rotation of results from large numbers of biological samples in pharmaceutical industry makes high throughput bioanalysis more essential. In this article, high-throughput sample preparation techniques are presented; examples are given of the extraction and concentration of analytes from biological matrices, including protein precipitation, solid-phase extraction, liquid-liquid extraction and microextraction-related techniques. Finally, the potential role of selective extraction methods, including molecular imprinted phases, is considered.
|
|
| 4. |
- Ayoglu, Burcu, et al.
(författare)
-
Antigen arrays for profiling autoantibody repertoires
- 2016
-
Ingår i: Bioanalysis. - : FUTURE SCI LTD. - 1757-6180 .- 1757-6199. ; 8:10, s. 1105-1126
-
Forskningsöversikt (refereegranskat)abstract
- Autoantibodies are a key component for the diagnosis, prognosis and monitoring of various diseases. In order to discover novel autoantibody targets, highly multiplexed assays based on antigen arrays hold a great potential and provide possibilities to analyze hundreds of body fluid samples for their reactivity pattern against thousands of antigens in parallel. Here, we provide an overview of the available technologies for producing antigen arrays, highlight some of the technical and methodological considerations and discuss their applications as discovery tools. Together with recent studies utilizing antigen arrays, we give an overview on how the different types of antigen arrays have and will continue to deliver novel insights into autoimmune diseases among several others.
|
|
| 5. |
- Barroso, MG, et al.
(författare)
-
A validated method for the determination of hematocrit in dried blood spots using image analysis
- 2023
-
Ingår i: Bioanalysis. - : Future Science Ltd. - 1757-6199 .- 1757-6180. ; 15:6, s. 331-341
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: To develop a nondestructive method for the estimation of hematocrit (HCT) in dried blood spots (DBSs). Materials & methods: Standards and controls were created (HCT range: 0.20–0.50 l/l) and DBS scanned using a flatbed scanner. Gray values and pixel areas were analyzed with open-source software to estimate HCT and volume, respectively. HCT obtained in whole blood using hematological analyzer was compared with DBS scanner method (n = 50). Results: Between-run precision was 4.7–10.2% and between-run accuracy was 89.6–102.1%. In the hematological instrument comparison, 96% of the patient sample results were within ±15%. Conclusion: The nondestructive method can be used to exclude patient DBS samples with extreme HCT levels from further analysis and avoid bias on measured concentration.
|
|
| 6. |
- Beck, O, et al.
(författare)
-
Methods for urine drug testing using one-step dilution and direct injection in combination with LC-MS/MS and LC-HRMS
- 2014
-
Ingår i: Bioanalysis. - : Future Science Ltd. - 1757-6199 .- 1757-6180. ; 6:17, s. 2229-2244
-
Tidskriftsartikel (refereegranskat)abstract
- The advent of LC combined with MS made it possible to design analytical methods for urine drug testing based on the very simple concept of diluting urine with an internal standard as the sole preparation procedure prior to instrumental analysis. The number of publications using this method design increased after the development of high-efficiency LC based on sub-2 μm particles. The success of this method design for drug testing, doping control and toxicological investigations of urine is now well documented and comprise both screening and confirmation methods. The nondiscriminating nature of this method design makes it even more attractive in combination with high-resolution MS for multicomponent target and general unknown analysis applications.
|
|
| 7. |
- Bergqvist, Yngve, et al.
(författare)
-
In memory of Niklas Lindegardh
- 2012
-
Ingår i: Bioanalysis. - 1757-6180 .- 1757-6199. ; 4:6, s. 751-751
-
Tidskriftsartikel (refereegranskat)
|
|
| 8. |
- Birgersson, Sofia, 1976, et al.
(författare)
-
A high-throughput LC-MS/MS assay for quantification of artesunate and its metabolite dihydroartemisinin in human plasma and saliva.
- 2014
-
Ingår i: Bioanalysis. - : Future Science Ltd. - 1757-6180 .- 1757-6199. ; 6:18, s. 2357-69
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: Saliva is an alternative sampling matrix to plasma, offering a noninvasive technique, but requires a highly sensitive bioanalytical method. MATERIALS & METHODS: An API 3000 triple quadrupole mass spectrometer with an electrospray ionization source operated in the positive ion mode was used for the analysis. RESULTS: A high-throughput LC-MS/MS method using SPE for the quantification of artesunate and dihydroartemisinin in plasma and saliva has been optimized and validated according to US FDA guidelines. For both analytes the LLOQ was determined to 5 ng/ml and the calibration range was 5-1000 ng/ml for artesunate and 5-2000 ng/ml for dihydroartemisinin. CONCLUSION: For the first time, a bioanalytical method for determination of artesunate and dihydroartemisinin in human saliva has been described, showing possible applicability in clinical saliva samples in addition to plasma samples.
|
|
| 9. |
- Blessborn, Daniel, et al.
(författare)
-
Assay for screening for six antimalarial drugs and one metabolite using dried blood spot sampling, sequential extraction and ion-trap detection
- 2010
-
Ingår i: Bioanalysis. - : Future Science Ltd. - 1757-6180 .- 1757-6199. ; 2:11, s. 1839-1847
-
Tidskriftsartikel (refereegranskat)abstract
- Background: More parasites are becoming resistant to antimalarial drugs, and in many areas a change in first-line drug treatment is necessary. The aim of the developed assay is to help determine drug use in these areas and also to be a complement to interviewing patients, which will increase reliability of surveys.Results: This assay detects quinine, mefloquine, sulfadoxine, pyrimethamine, lumefantrine, chloroquine and its metabolite desethylchloroquine in a 100-mu l dried blood spot. Most of the drugs also have long half-lives that make them detectable at least 7 days after administration. The drugs are extracted from the dried blood spot with sequential extraction (due to the big differences in physicochemical properties), solid-phase extraction is used as sample clean-up and separation is performed with gradient-LC with MS ion-trap detection.Conclusion: Detection limits (S/N > 5:1) at 50 ng/ml or better were achieved for all drugs except lumefantrine (200 ng/ml), and thus can be used to determine patient compliance. A major advantage of using the ion-trap MS it that it will be possible to go back into the data and look for other drugs as needed.
|
|
| 10. |
- Blessborn, D., et al.
(författare)
-
Heat stabilization of blood spot samples for determination of metabolically unstable drug compounds
- 2013
-
Ingår i: Bioanalysis. - : Future Science Ltd. - 1757-6180 .- 1757-6199. ; 5:1, s. 31-39
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Sample stability is critical for accurate analysis of drug compounds in biosamples. The use of additives to eradicate the enzymatic activity causing loss of these analytes has its limitations. Results: A novel technique for sample stabilization by rapid, high-temperature heating was used. The stability of six commercial drugs in blood and blood spots was investigated under various conditions with or without heat stabilization at 95 degrees C. Oseltamivir, cefotaxime and ribavirin were successfully stabilized by heating whereas significant losses were seen in unheated samples. Amodiaquine was stable with and without heating. Artemether and dihydroartemisinin were found to be very heat sensitive and began to decompose even at 60 degrees C. Conclusion: Heat stabilization is a viable technique to maintain analytes in blood spot samples, without the use of chemical additives, by stopping the enzymatic activity that causes sample degradation.
|
|
