Sampling and Sample Handling

2007 ◽  
pp. 183-224
Keyword(s):  
Sample Handling

X-Ray Analysis of Frozen Hydrated Sections:The Unconventional Approach

1982 ◽  
Vol 40 ◽  
pp. 754-757
Author(s):  
R. Beeuwkes ◽  
A. Saubermann ◽  
P. Echlin ◽  
S. Churchill
Keyword(s):  
Ratio Method ◽  
Frozen Sections ◽  
Technical Problems ◽  
Sample Handling ◽  
X Ray ◽  
Common Group ◽  
Ideal Method ◽  
Classic Paper ◽  
Physical Principles ◽  
The Ideal

Fifteen years ago, Hall described clearly the advantages of the thin section approach to biological x-ray microanalysis, and described clearly the ratio method for quantitive analysis in such preparations. In this now classic paper, he also made it clear that the ideal method of sample preparation would involve only freezing and sectioning at low temperature. Subsequently, Hall and his coworkers, as well as others, have applied themselves to the task of direct x-ray microanalysis of frozen sections. To achieve this goal, different methodological approachs have been developed as different groups sought solutions to a common group of technical problems. This report describes some of these problems and indicates the specific approaches and procedures developed by our group in order to overcome them. We acknowledge that the techniques evolved by our group are quite different from earlier approaches to cryomicrotomy and sample handling, hence the title of our paper. However, such departures from tradition have been based upon our attempt to apply basic physical principles to the processes involved. We feel we have demonstrated that such a break with tradition has valuable consequences.

Stability of antioxidant vitamins in whole human blood during overnight storage at 4°C and frozen storage up to 6 months

2018 ◽  
Vol 88 (3-4) ◽  
pp. 151-157 ◽  
Author(s):  
Scott W. Leonard ◽  
Gerd Bobe ◽  
Maret G. Traber
Keyword(s):  
Ascorbic Acid ◽  
Whole Blood ◽  
Healthy Subjects ◽  
Frozen Storage ◽  
Blood Collection ◽  
Plasma Samples ◽  
Optimal Conditions ◽  
Plasma Ascorbic Acid ◽  
Blood Samples ◽  
Sample Handling

Abstract. To determine optimal conditions for blood collection during clinical trials, where sample handling logistics might preclude prompt separation of erythrocytes from plasma, healthy subjects (n=8, 6 M/2F) were recruited and non-fasting blood samples were collected into tubes containing different anticoagulants (ethylenediaminetetra-acetic acid (EDTA), Li-heparin or Na-heparin). We hypothesized that heparin, but not EDTA, would effectively protect plasma tocopherols, ascorbic acid, and vitamin E catabolites (α- and γ-CEHC) from oxidative damage. To test this hypothesis, one set of tubes was processed immediately and plasma samples were stored at −80°C, while the other set was stored at 4°C and processed the following morning (~30 hours) and analyzed, or the samples were analyzed after 6 months of storage. Plasma ascorbic acid, as measured using HPLC with electrochemical detection (LC-ECD) decreased by 75% with overnight storage using EDTA as an anticoagulant, but was unchanged when heparin was used. Neither time prior to processing, nor anticoagulant, had any significant effects upon plasma α- or γ-tocopherols or α- or γ-CEHC concentrations. α- and γ-tocopherol concentrations remained unchanged after 6 months of storage at −80°C, when measured using either LC-ECD or LC/mass spectrometry. Thus, refrigeration of whole blood at 4°C overnight does not change plasma α- or γ-tocopherol concentrations or their catabolites. Ascorbic acid is unstable in whole blood when EDTA is used as an anticoagulant, but when whole blood is collected with heparin, it can be stored overnight and subsequently processed.

All-Contactless Measurement of Series Resistance Distributions on Solar Cells with Photoluminescence Imaging

2011 ◽  
Author(s):  
M. Kasemann ◽  
L.M. Reindl ◽  
B. Michl ◽  
W. Warta ◽  
A. Schütt ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Current Flow ◽  
Series Resistance ◽  
Electrical Contacts ◽  
New Method ◽  
Contactless Measurement ◽  
Sample Handling ◽  
Imaging Methods ◽  
Lateral Current

Abstract Conventional series resistance imaging methods require electrical contacts for current injection or extraction in order to generate lateral current flow in the solar cell. This paper presents a new method to generate lateral current flow in the solar cell without any electrical contacts. This reduces the sample handling complexity for inline application and allows for measurements on unfinished solar cell precursors.

Busting Myths in Compound Handling Practices for Assay Developers

2021 ◽  
pp. 247263032110233
Author(s):  
Rosalia Gonzales ◽  
Travis Mathewson ◽  
Jefferson Chin ◽  
Holly McKeith ◽  
Lane Milde ◽  
...  
Keyword(s):  
The Other ◽  
Common Goal ◽  
Collaborative Relationship ◽  
Sample Handling ◽  
Root Cause ◽  
The Common ◽  
Recommended Practices ◽  
Handling Practices ◽  
The One

Since the advent of modern-day screening collections in the early 2000s, various aspects of our knowledge of good handling practices have continued to evolve. Some early practices, however, continue to prevail due to the absence of defining data that would bust the myths of tradition. The lack of defining data leads to a gap between plate-based screeners, on the one hand, and compound sample handling groups, on the other, with the latter being the default party to blame when an assay goes awry. In this paper, we highlight recommended practices that ensure sample integrity and present myth busting data that can help determine the root cause of an assay gone bad. We show how a strong and collaborative relationship between screening and sample handling groups is the better state that leads to the accomplishment of the common goal of finding breakthrough medicines.

scholarly journals Advantageous Uses of Mass Spectrometry for the Quantification of Proteins

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
John E. Hale
Keyword(s):  
Mass Spectrometry ◽  
Great Difficulty ◽  
Immunological Methods ◽  
Regulatory Agencies ◽  
Protein Species ◽  
Sample Handling ◽  
Wide Acceptance ◽  
Immunological Assays ◽  
Protein Assays ◽  
Very High

Quantitative protein measurements by mass spectrometry have gained wide acceptance in research settings. However, clinical uptake of mass spectrometric protein assays has not followed suit. In part, this is due to the long-standing acceptance by regulatory agencies of immunological assays such as ELISA assays. In most cases, ELISAs provide highly accurate, sensitive, relatively inexpensive, and simple assays for many analytes. The barrier to acceptance of mass spectrometry in these situations will remain high. However, mass spectrometry provides solutions to certain protein measurements that are difficult, if not impossible, to accomplish by immunological methods. Cases where mass spectrometry can provide solutions to difficult assay development include distinguishing between very closely related protein species and monitoring biological and analytical variability due to sample handling and very high multiplexing capacity. This paper will highlight several examples where mass spectrometry has made certain protein measurements possible where immunological techniques have had a great difficulty.

Sample handling substantially affects Johne's ELISA

2009 ◽  
Vol 90 (3-4) ◽  
pp. 278-283 ◽  
Author(s):  
Catherine A. Alinovi ◽  
Michael P. Ward ◽  
Tsang Long Lin ◽  
Ching Ching Wu
Keyword(s):  
Sample Handling

Sample handling and processing on Mars for future astrobiology missions

2011 ◽  
Author(s):  
Luther Beegle ◽  
James P. Kirby ◽  
Anita Fisher ◽  
Robert Hodyss ◽  
Alison Saltzman ◽  
...  
Keyword(s):  
Sample Handling

A Downhole Passive Sampling System To Avoid Bias and Error from Groundwater Sample Handling

2010 ◽  
Vol 44 (13) ◽  
pp. 4917-4923 ◽  
Author(s):  
Sanford L. Britt ◽  
Beth L. Parker ◽  
John A. Cherry
Keyword(s):  
Passive Sampling ◽  
Groundwater Sample ◽  
Sampling System ◽  
Sample Handling

Reassessment of plasma angiotensins measurement: Effects of protease inhibitors and sample handling procedures

Peptides ◽  
1991 ◽  
Vol 12 (5) ◽  
pp. 1135-1141 ◽  
Author(s):  
Katsuhiko Kohara ◽  
Yoshikatsu Tabuchi ◽  
Preenie Senanayake ◽  
K.Bridget Brosnihan ◽  
Carlos M. Ferrario
Keyword(s):  
Protease Inhibitors ◽  
Sample Handling ◽  
Measurement Effects
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