Biochemical aspects of aldehyde fixation and a new formaldehyde fixative

Artvinli, Suad

doi:10.1007/bf01003881

Cited by 13 publications

(8 citation statements)

References 23 publications

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“…47 Conversely, it has also been suggested that formalin fixation results in partial denaturation of proteins, which might aVect their tertiary structure. 48 The mechanisms by which formaldehyde fixes tissue and the extent of protein denaturation that occurs during fixation remain unclear.…”

Section: Discussionmentioning

confidence: 99%

Detection of progesterone receptor forms A and B by immunohistochemical analysis

Mote

2001

Journal of Clinical Pathology

103

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Aim-The measurement of progesterone receptors (PR) is recommended as part of the clinical management of breast and endometrial cancers, and immunohistochemistry on formalin fixed tissue is now the method of choice. PR is expressed as two isoforms, PRA and PRB, and although both these proteins are expressed in hormone dependent cancers, there is evidence that a large proportion of tumours express a predominance of one isoform. Therefore, it is essential to document the individual detection of PRA and PRB by the presently available anti-PR antibodies. The aim of this study is to investigate the detection of PR isoforms A and B in formalin fixed, paraYn wax embedded cell lines and tissue sections by immunohistochemistry, using a panel of commercial and in house antibodies to human PR. Methods-PR negative cell lines stably transfected to express only PRA (MCF7Mll/PRA) or PRB (MDA-MB-231/PRB), and tissue sections of human breast carcinoma and normal endometrium were stained using an immunoperoxidase method. A panel of primary PR specific antibodies was evaluated for ability to detect both PRA and PRB proteins, and for intensity and distribution of positive staining under optimal conditions. Results-Of the 11 antibodies assessed, only four recognised PRA and PRB similarly. Six recognised PRA proteins but were unable to detect PRB expression in the cell lines expressing only PRA or PRB. In tissues expressing high amounts of PRA and PRB, all antibodies tested demonstrated positive PR staining. However, in tissues expressing a predominance of PRB, diVerential staining patterns were observed, with variations in staining intensity and in the proportion of cells positive for PR. Conclusions-Most PR specific antibodies tested failed to detect PRB in formalin fixed tissue by immunohistochemical techniques, despite their ability to do so by immunoblot analysis. These observations suggest that there are conformational differences between PRA and PRB that mask epitopes on the PRB protein recognised by most anti-PR antibodies. The selection of antibodies that recognise both PRB and PRA in formalin fixed tissue is essential for the accurate evaluation of PR positivity in clinical specimens. (J Clin Pathol 2001;54:624-630)

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Section: Discussionmentioning

confidence: 99%

Detection of progesterone receptor forms A and B by immunohistochemical analysis

Mote

2001

Journal of Clinical Pathology

103

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“…Inhibition was done by immersing the biomass (previous washed with PBS-phosphate buffered saline) in 2.5 % (v/v) of a glutaraldehyde solution and 37 % of formaldehyde. These two aldehyde fixatives are frequently used in light and electron microscopy (Artvinli 1975).…”

Section: Adsorption Of Ery B On Biomassmentioning

confidence: 99%

Biological decolorization of xanthene dyes by anaerobic granular biomass

Apostol

Pereira

et al. 2012

Biodegradation

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Biodegradation of a xanthene dyes was investigated for the first time using anaerobic granular sludge. On a first screening, biomass was able to decolorize, at different extents, six azo dye solutions: acid orange 7, direct black 19, direct blue 71, mordant yellow 10, reactive red 2 and reactive red 120 and two xanthene dyes--Erythrosine B and Eosin Y. Biomass concentration, type of electron donor, induction of biomass with dye and mediation with activated carbon (AC) were variables studied for Erythrosine B (Ery) as model dye. Maximum color removal efficiency was achieved with 4.71 g VSS L⁻¹, while the process rates were independent of the biomass concentration above 1.89 g VSS L⁻¹. No considerable effects were observed when different substrates were used as electron donors (VFA, glucose or lactose). Addition of Ery in the incubation period of biomass led to a fivefold increase of the decolorization rate. The rate of Ery decolorization almost duplicated in the presence of commercial AC (0.1 g L⁻¹ AC₀). Using different modified AC samples (from the treatment of AC₀), a threefold higher rate was obtained with the most basic one, AC(H₂), as compared with non-mediated reaction. Higher rates were obtained at pH 6.0. Chemical reduction using Na₂S confirmed the recalcitrant nature of this dye. The results attest that decolorization of Ery is essentially due to enzymatic and adsorption phenomena.

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“…From the freshly excised muscle, tissue blocks of approximately 2mm thick were obtained. They immediately fixed in bicarbonate formaldehyde (Artvinli 1975) for a very short time at room temperature. Dehydration was done with graded ethanol pre pared in saline and with propylene oxide.…”

Section: Methodsmentioning

confidence: 99%