Fixation of Histology Samples: Principles, Methods and …

5.1 Description of Nature of Fixation. 1. Immersion fixation: This is the commonest way of fixation in the laboratories. In this technique the whole specimen is immersed in the liquid fixative such as tissue samples are immersed in 10% neutral buffered formalin or cytology smear in 95% ethyl alcohol. 2.

Formaldehyde | Medical Management Guidelines | Toxic …

Formaldehyde is a nearly colorless gas with a pungent, irritating odor even at very low concentrations (below 1 ppm). Its vapors are flammable and explosive. Because the pure gas tends to polymerize, it is commonly used and stored in solution. Formalin, the aqueous solution of formaldehyde (30% to 50% formaldehyde), typically contains up to 15% …

Conserve O Gram

formalin fixative to 70 % ethanol, it would be best to place it in staged solutions of 20%, 40%, and 60% ethanol for 24 hours each before placing it in the permanent fixative concentration of 70 % ethanol. See Conserve O Gram 11/1 for detailed instructions for transferring specimens from formalin to other preservatives.

Alcohol-Based Fixatives can Better Preserve Tissue Morphology than Formalin

SUMMARY: Fixation is a crucial step in processing of tissue specimen for preservation of cellular architecture and composition. of cells. Alcohol-based fixatives are considered some of the most ...

Comparison of Formalin-Ethyl Ether Sedimentation, Formalin-Ethyl …

Formalin-ethyl ether sedimentation, Formalin-ethyl acetate sedimentation, and zinc sulfate flotation techniques were compared using over 250 clinical parasitol-ogy specimens. Fifty positive specimens were identified, and a variety of parasites, ... Disadvantages that accrue from this technique are that the concentration is time 884 TRUANT ET AL ...

Comparison of formalin-ethyl ether sedimentation, formalin …

The results indicate that the Formalin-ethyl acetate procedure provides a suitable alternative to the Formalin-ether method, and they demonstrate the value of using both …

Faecal Parasitology: Concentration Methodology Needs to …

Since the polarity and miscibility indices of ether result in its being a better fat extractor than ethyl acetate, the surfactant Triton X 100 is added to the faecal/formalin solution to compensate if ethyl acetate is used. Triton X 100 helps ethyl acetate to break up faecal matter and results in a less dense deposit, thus facilitating the ...

Comparison of the Flotac-400 Dual Technique and the Formalin …

The formalin-ether concentration technique (FECT) is a widely used sedimentation technique for the diagnosis of intestinal protozoa in preserved stool samples . The most commonly used fixatives for stool preservation are either formalin or sodium acetate-acetic acid-formalin (SAF) (3, 24, 40). Of note, the FECT has some drawbacks.

MLAB1331 Lab Manual

C. Formalin-Ethyl Acetate Procedure . 1. Label a fecal concentration tube (the flat-bottomed container) for each stool to be examined. ... The disadvantages of this method are that it requires some technical expertise to set up the slide culture, and there is a waiting period for incubation of the slide culture in addition to incubation on the ...

Formal Ether Sedimentation Technique • Microbe Online

1. Certain parasites, such as Giardia lamblia, hookworm eggs, and Trichuris eggs may not concentrate well from PVA-preserved specimens. The oocysts of Isospora bellido not routinely appear in concentr...
2. With both the sedimentation and the flotation techniques, species identification may not be possible in all cases, depending on the clarity of the forms observed. Permanently stained s…

1. Certain parasites, such as Giardia lamblia, hookworm eggs, and Trichuris eggs may not concentrate well from PVA-preserved specimens. The oocysts of Isospora bellido not routinely appear in concentr...
2. With both the sedimentation and the flotation techniques, species identification may not be possible in all cases, depending on the clarity of the forms observed. Permanently stained smears are usu...

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Formaldehyde

Formalin is a 40% solution of formaldehyde in water. It has been used for many years in concentrations of 2–4% to treat radiation-induced hemorrhagic proctitis. Only a few minor complications have been reported after treatment – acute proctitis, worsening of radiation-induced strictures, worsening of incontinence, and severe pain ( 6c, 7c ).

Innovative Cadaver Preservation Techniques: a Systematic …

Imperial College London soft-preservation (ICL-SP) solution. The ICL-SP solution technique is used in the Imperial College, London, and is based on alcohol, water, glycerol and phenol (soft-preserved) rather than fixed in formalin. Cadavers embalmed by this method can be used for about six months.

Comparison of Fixation Methods for Preservation Cytology …

However, there are also disadvantages to using NBF as a fixative, including the handling of formalin, since formaldehyde is considered a carcinogen and crosslinking agent . The most commonly used fixatives for diagnostic pathology and cytologic specimens are 10% NBF and 95% ethanol . In our institution, 96% alcohol used by clinicians as a ...

CDC

Commercial two-vials kits are available for this purpose. Preserved specimens can be stored for several months. For additional information on stool collection, call the Division of Parasitic Diseases at (404) 718-4110. …

Evaluation of Formalin — Acetone Sedimentation in the

To overcome these disadvantages, ... Four specimens were negative by the Formalin-ethyl acetate method and two by the FeKal system. These false-negative observations occurred in specimens with low ...

TropicalMed | Free Full-Text | Diagnostic Techniques of Soil

The objective of this review was to describe the advantages and disadvantages of the different available techniques for the diagnosis of STH infections and to highlight their use in control programs. ... The stool samples can be fixed with either sodium acetate-acetic acid-formalin (SAF), or ... After adding ether or ethyl acetate, the mixed ...

A comparative study of formalin-ethyl acetate …

All the positive samples were processed by both the standard methodology, i.e., formalin-ethyl acetate sedimentation technique and Mini Parasep ® SF method, by the standard operating procedure of our laboratory and the manufacturer's instruction. Stool pellet concentrates were subjected to saline/iodine wet mount, modified acid fast staining ...

Formalin-ethyl acetate concentration, FLOTAC Pellet and …

These infections are mainly associated with faecal contamination, lack of safe drinking water and sewage services as well as with an inadequate hygiene …

Comparison of formalin-ethyl ether sedimentation, formalin …

Formalin-ethyl ether sedimentation, Formalin-ethyl acetate sedimentation, and zinc sulfate flotation techniques were compared using over 250 clinical parasitology …

Re-evaluation of the formalin-ether sedimentation method …

The re-evaluated aspects of FES and suggested that the modifi ed FES is effective and better for the recovery of parasite ova in areas of low-intensity parasitic infection. The formalin-ether sedimentation (FES) method is considered as reliable method of fecal examination for the detection of parasites. In this study, we re-evaluated several aspects …

Comparing the efficiency of four diagnostic

With regard to advantages and disadvantages of each reagent, and the performance evaluation of each concentration methods, this study demonstrated that the combined use of parasitological techniques is important for the diagnosis of all intestinal parasites particularly in the specimens with low intensity infection. ... Comparison of …

Performance of Mini Parasep

Formalin-ethyl acetate concentration technique (FECT) Fecal examination using a modified FECT diagnostic method was conducted as reported previously [23, 24]. Briefly, fecal samples were homogenized, and 2 g of fresh feces was weighed and diluted in 7 ml of 10% formalin solution and strained through two layers of gauze into the 15-ml …

Fixing Samples for IHC: Tips and Trick

Disadvantages; Whole Animal Perfusion Fixation: Perfusion of 4% paraformaldehyde solution through the vascular system: For large, intact tissue of small animals. ... Formalin is thought to preserve tissue morphology better than alcohol fixatives. However, alcohol fixation better preserves antigen and antigenicity. ...

Fixation and Fixatives: Roles and Functions—A …

Fixation is considered as physiochemical proc ess where cells or tissues are fixed c hem. ically. Fixatives perform various functions such as prev ention of autolysis and tissue. putrefaction ...

Comparison Formalin-Ethyl Ether Sedimentation, …

ComparisonofFormalin-Ethyl EtherSedimentation, Formalin-EthylAcetate Sedimentation, andZinc Sulfate Flotation Techniquesfor Detection ofIntestinal Parasites ALLANL. ... Disadvantages that accrue from this technique are that the concentration is time VOL.13, 1981. 884 TRUANTET AL. consuming andconfusing debris mayremainin

Alcoholic fixation over formalin fixation: A new, safer option …

Formalin is a widely used fixative but there is potential public health risks to exposure. Besides, alcoholic fixation is advantageous over formalin fixation because of faster fixation, optimal preservation and safer workplace environment. Following fixation by EMA and 10% neutral buffered formalin …

Formal Ether Concentration Technique-Introduction, Principle

Add 1 to 2 ml of ethyl acetate, Stopper the tube, and shake vigorously. Centrifuge at 1500 rpm for 10 minutes. Four layers should result as a top layer of ethyl acetate, plug of debris, layer of formalin, and sediment respectively. Free the plug of debris from the side of the tube by ringing with an applicator stick.

Faecal Parasitology: Concentration Methodology Needs to …

Although ethyl acetate is less flammable, less combustible and more stable than ether, it results in a thicker deposit. However the addition of Triton X 100 to the …

A field evaluation of formalin–gasoline technique in the

A field evaluation of the formalin–gasoline procedure to detect parasite ova, cysts, or larvae from 470 fecal specimens (comprising both fresh and formalin-preserved stool samples) was compared with that of the formalin–ether sedimentation technique. Parallel concentrates with diethyl ether and gasoline were prepared for each specimen, …