Ethanol Fixation Protocol v1

protocols.io ◽  
2016 ◽  
Author(s):  
Kelsey Miller
Keyword(s):  
Fixation Protocol

scholarly journals A perfusion-fixation procedure for the concurrent demonstration of Timm's, horseradish peroxidase (HRP), and acethycholinesterase (AChE) histochemistry.

1984 ◽  
Vol 32 (10) ◽  
pp. 1113-1116 ◽  
Author(s):  
M B Moss ◽  
D L Rosene
Keyword(s):  
Horseradish Peroxidase ◽  
Sodium Sulfide ◽  
Prolonged Exposure ◽  
Initial Exposure ◽  
Sodium Sulfide Solution ◽  
Acetylcholinesterase Histochemistry ◽  
The Central Nervous System ◽  
Fixation Protocol ◽  
Perfusion Fixation ◽  
Sulfide Solution

The sulfide-silver method of Timm has been a widely used histochemical technique to demonstrate the presence of heavy metals in biological tissue, particularly in the central nervous system. However, the use of this method or its several modifications results in less than optimal morphological preservation and requires embedding the tissue in paraffin or freezing it and cutting it directly onto slides with a cryostat. These procedures can decrease the sensitivity and limit the application of other histochemical procedures, particularly when experiments necessitate processing large specimens or reaction procedures require techniques using free-floating sections. A perfusion-fixation protocol is described that yields sufficient fixation to cut whole frozen blocks of tissue with a sliding microtome, permits the use of free-floating sections, and allows the concurrent demonstration of horseradish peroxidase and acetylcholinesterase histochemistry without loss of sensitivity. The method consists of a short initial exposure to a sodium sulfide solution followed by a prolonged exposure to a combined sulfide-aldehyde fixative solution.

scholarly journals The effect of methanol fixation on single-cell RNA sequencing data

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xinlei Wang ◽  
Lei Yu ◽  
Angela Ruohao Wu
Keyword(s):  
Single Cell ◽  
Rna Sequencing ◽  
Gc Content ◽  
Sequencing Data ◽  
Rna Integrity ◽  
Construction Methods ◽  
Single Cell Rna Sequencing ◽  
Health And Disease ◽  
Fixation Protocol

Abstract Background Single-cell RNA sequencing (scRNA-seq) has led to remarkable progress in our understanding of tissue heterogeneity in health and disease. Recently, the need for scRNA-seq sample fixation has emerged in many scenarios, such as when samples need long-term transportation, or when experiments need to be temporally synchronized. Methanol fixation is a simple and gentle method that has been routinely applied in scRNA-sEq. Yet, concerns remain that fixation may result in biases which may change the RNA-seq outcome. Results We adapted an existing methanol fixation protocol and performed scRNA-seq on both live and methanol fixed cells. Analyses of the results show methanol fixation can faithfully preserve biological related signals, while the discrepancy caused by fixation is subtle and relevant to library construction methods. By grouping transcripts based on their lengths and GC content, we find that transcripts with different features are affected by fixation to different degrees in full-length sequencing data, while the effect is alleviated in Drop-seq result. Conclusions Our deep analysis reveals the effects of methanol fixation on sample RNA integrity and elucidates the potential consequences of using fixation in various scRNA-seq experiment designs.

scholarly journals Coimbatore Orthopedic Surgical Fixation Protocol in COVID-19 Pandemic—Our Experience

2021 ◽  
Vol 3 (1) ◽  
pp. 1-6
Author(s):  
Vetrivel Chezian Sengodan ◽  
Mugundhan Moongilpatti Sengodan ◽  
Ramachandran Perumal
Keyword(s):  
Surgical Fixation ◽  
Fixation Protocol

scholarly journals Making a science out of preanalytics: An analytical method to determine optimal tissue fixation in real-time

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258495
Author(s):  
Daniel R. Bauer ◽  
Torsten Leibold ◽  
David R. Chafin
Keyword(s):  
Real Time ◽  
Analytical Method ◽  
Digital Pathology ◽  
Innovative Technology ◽  
Tissue Fixation ◽  
Predictive Algorithm ◽  
Dynamic Fixation ◽  
Fixation Techniques ◽  
Fixation Protocol ◽  
Standard Fixation

Modern histopathology is built on the cornerstone principle of tissue fixation, however there are currently no analytical methods of detecting fixation and as a result, in clinical practice fixation is highly variable and a persistent source of error. We have previously shown that immersion in cold formalin followed by heated formalin is beneficial for preservation of histomorphology and have combined two-temperature fixation with ultra-sensitive acoustic monitoring technology that can actively detect formalin diffusing into a tissue. Here we expand on our previous work by developing a predictive statistical model to determine when a tissue is properly diffused based on the real-time acoustic signal. We trained the model based on the morphology and characteristic diffusion curves of 30 tonsil cores. To test our model, a set of 87 different tonsil samples were fixed with four different protocols: dynamic fixation according to our predictive algorithm (C/H:Dynamic, N = 18), gold-standard 24 hour room temperature (RT:24hr, N = 24), 6 hours in cold formalin followed by 1 hour in heated formalin (C/H:6+1, N = 21), and 2 hours in cold formalin followed by 1 hour in heated formalin (C/H:2+1, N = 24). Digital pathology analysis revealed that the C/H:Dynamic samples had FOXP3 staining that was spatially uniform and statistically equivalent to RT:24hr and C/H:6+1 fixation protocols. For comparison, the intentionally underfixed C/H:2+1 samples had significantly suppressed FOXP3 staining (p<0.002). Furthermore, our dynamic fixation protocol produced bcl-2 staining concordant with standard fixation techniques. The dynamically fixed samples were on average only submerged in cold formalin for 4.2 hours, representing a significant workflow improvement. We have successfully demonstrated a first-of-its-kind analytical method to assess the quality of fixation in real-time and have confirmed its performance with quantitative analysis of downstream staining. This innovative technology could be used to ensure high-quality and standardized staining as part of an expedited and fully documented preanalytical workflow.

scholarly journals Effect of methanol fixation on single-cell RNA sequencing data

2020 ◽  
Author(s):  
Xinlei Wang ◽  
Lei Yu ◽  
Angela Wu
Keyword(s):  
Single Cell ◽  
Rna Sequencing ◽  
Gc Content ◽  
Sequencing Data ◽  
Rna Integrity ◽  
Construction Methods ◽  
Single Cell Rna Sequencing ◽  
Health And Disease ◽  
Fixation Protocol

AbstractSingle-cell RNA sequencing (scRNA-seq) has led to remarkable progress in our understanding of tissue heterogeneity in health and disease. Recently, the need for scRNA-seq sample fixation has emerged in many scenarios, such as when samples need long-term transportation, or when experiments need to be temporally synchronized. Methanol fixation is a simple and gentle method that has been routinely applied in scRNA-seq. Yet, concerns remain that fixation may result in biases which may change the RNA-seq outcome. We adapted an existing methanol fixation protocol and performed scRNA-seq on both live and methanol fixed cells. Analyses of the results show methanol fixation can faithfully preserve biological related signals, while the discrepancy caused by fixation is subtle and relevant to library construction methods. By grouping transcripts based on their lengths and GC content, we find that transcripts with different features are affected by fixation to different degrees in full-length sequencing data, while the effect is alleviated in Drop-seq result. Our deep analysis reveals the effects of methanol fixation on sample RNA integrity and elucidates the potential consequences of using fixation in various scRNA-seq experiment designs.

Visualization of capsular polysaccharide of coagulase negative staphylococci (CNS) associated with vascular prosthetic graft material

1990 ◽  
Vol 48 (3) ◽  
pp. 838-839
Author(s):  
Michael P. Goheen ◽  
Charles E. Edmiston ◽  
Saeed A. Khan ◽  
Nancy K. Maguire ◽  
David D. Schmitt
Keyword(s):  
Capsular Polysaccharide ◽  
Clinical Importance ◽  
Prosthetic Graft ◽  
Graft Material ◽  
Coagulase Negative Staphylococci ◽  
Transmission Electron ◽  
Etiologic Agents ◽  
Fixation Protocol ◽  
Capsular Material ◽  
Reference Strains

The coagulase negative staphylococci (CNS) are a ubiquitous group of microorganisms which comprise a major component of the microbial flora of the skin and adjacent glands. Historically, the CNS were viewed as insignificant contaminants with little clinical importance. However, over the last decade these organisms have emerged as important etiologic agents of biomaterial associated infections. Furthermore, many of the Staphylococcus epidermidis strains recovered from catheter or prosthetic infections exhibit the capacity to produced an extracellular capsular polysaccharide (slime) which is viewed as an important factor in biomaterial adherence and persistence. Bacterial capsular material is composed of hydrated polysaccharides and has been visualized by transmission electron microscopy when lysine is added to the fixation protocol. This study reports on the use of a lysine-ruthenium redglutaraldehyde fixation technique for visualizing the polysaccharide capsule on two coagulase negative staphylococcal reference strains, S. epidermidis RP62A (ATCC 35984) and S. hominis SP2 (ATCC 35982).

A Shorter Fixation Protocol for Transmission Electron Microscopy: An Alternative to Spend Less Time

2009 ◽  
Vol 33 (4) ◽  
pp. 169-174 ◽  
Author(s):  
Fernando de S. F. Guimarães ◽  
Simone M. de Oliveira ◽  
Carolina C. de Oliveira ◽  
Lucélia Donatti ◽  
Dorly de Freitas Buchi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Transmission Electron ◽  
Fixation Protocol

Ultrastructural changes in the progress of natural Scrapie regardless fixation protocol

2015 ◽  
Vol 144 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Rocío Sarasa ◽  
Concepción Junquera ◽  
Adolfo Toledano ◽  
Juan José Badiola ◽  
Marta Monzón
Keyword(s):  
Ultrastructural Changes ◽  
Natural Scrapie ◽  
Fixation Protocol

scholarly journals HOPE Fixation of Cytospin Preparations of Human Cells for In Situ Hybridization and Immunocytochemistry

2003 ◽  
Vol 51 (7) ◽  
pp. 977-980 ◽  
Author(s):  
Oliver Umland ◽  
Artur J. Ulmer ◽  
Ekkehard Vollmer ◽  
Torsten Goldmann
Keyword(s):  
In Situ Hybridization ◽  
Cultured Cells ◽  
Model System ◽  
Molecular Techniques ◽  
Stem Cell Line ◽  
Protection Effect ◽  
Fixation Protocol ◽  
Hope Fixation

In primary or cultured cells, in situ hybridization (ISH) or immunocytochemistry (ICC) is often performed on tissue that has been fixed by paraformaldehyde or Carnoy's. Recently we reported an optimized HOPE (HEPES–glutamic acid buffer-mediated organic solvent protection effect) fixation protocol for ISH targeting mRNA in lung tissues. We have now examined whether HOPE fixation could also be used on in vitro cultured cells for targeting mRNA by ISH or proteins by ICC on cytospin preparations. Using the myeloid stem cell line KG-1a as a model system, we showed that HOPE fixation can be applied for ISH and ICC on cultured cells. HOPE can be used with cells and tissues and with a broad spectrum of immunohistocytochemical and molecular techniques.

Sign in / Sign up

Export Citation Format

Share Document