Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Paraffin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

Interphase cytogenetics of gastric carcinoma: fluorescence in situ hybridization (FISH) applied to cells obtained from formalin-fixed paraffin-embedded tissues.

The interphase cytogenetics in formalin-fixed and paraffin-embedded gastric cancer tissues were examined by fluorescence in situ hybridization (FISH) with alpha-satellite DNA probes. Two gastric carcinoma cell lines, TMK-1 and MKN-28, were first analyzed cytogenetically. Of 25 TMK-1 cell karyotypes, chromosome 7 showed trisomy and chromosome 17 showed disomy in 18 cells. Most MKN-28 cells showed disomy of both chromosomes 7 and 17. Suspensions of singly isolated TMK-1 and MKN-7 cells were obtained from the cultured cells, and from paraffin-embedded tissue specimens fixed with formalin for 0, 1, 3 and 5 days obtained from xenotransplanted tumors in nude mice. The numbers of chromosomes 7 and 17 analyzed with the karyotypic preparations coincided well with those determined by FISH, even in the paraffin-embedded specimens. The number of tumor cells showing no signals, however, increased in the specimens after 5 days formalin fixation. In 10 surgically removed gastric carcinomas, the predominant signal number for chromosomes 7 and 17 in the cells of paraffin-embedded tissues was two (disomy), except in one papillary carcinoma, which was trisomic for chromosome 7. Large subpopulations (more than 20%) showing trisomy were found in four cases for chromosome 7 and in five cases for chromosome 17. A higher frequency of trisomy was found in well differentiated than in poorly differentiated carcinomas. These findings suggest that the FISH technique is a useful tool for detecting chromosomal aberrations in gastric adenocarcinoma cells, even in paraffin-embedded specimens, as long as the tissues are fixed with formalin for an appropriate time.

Adenocarcinoma↗

Demonstration of immunoglobulin in cryostat and paraffin sections of human tonsil by immunofluorescence and immunoperoxidase techniques. Effects of processing on immunohistochemical performance of tissues and on the use of proteolytic enzymes to unmask antigens in sections.

A fluorescein isothiocyanate (FITC) technique and one based on peroxidase-antiperoxidase (PAP) were used to study the distribution of immunoglobulin (Ig) in cryostat and paraffin sections of human tonsil. Trypsin and other proteolytic enzymes were used to 'unmask' the antigen in paraffin sections. The effects of processing, and particularly of fixation, on the immunohistochemical response of tissues were studied. The FITC and PAP methods detected Ig in paraffin and cryostat sections equally well. The distribution of the antigen was the same with both methods but the PAP method was the more informative. Formaldehyde-sucrose solution proved more suitable for fixing tissues for immunohistochemistry than glutaraldehyde. Trypsin revealed antigen in parraffin sections more efficiently than pepsin, papain, or pronase. Surface Ig (s-Ig) could be demonstrated in trypsinised paraffin sections but less effectively than in cryostat sections. Trypsinised paraffin sections were, however, more suitable for intracellular Ig (c-Ig) than cryostat sections although the performance of cryostat sections could be improved by prior fixation with a coagulative fixative.

Antigens↗

PCR detection of HIV proviral DNA (gag) in the brains of patients with AIDS: comparison between results using fresh frozen and paraffin wax embedded specimens.

AIMS: To adapt the polymerase chain reaction (PCR) technique of HIV detection to paraffin wax embedded brain tissue and to compare the results with those obtained using frozen tissue. METHODS: HIV antigen and HIV proviral DNA were detected in specimens of frontal lobe using immunohistochemistry and PCR, respectively. DNA was extracted from fresh tissue using standard methods whereas the technique for extracting DNA from paraffin wax embedded tissue was partly modified. RESULTS: Twenty cases were examined. HIV DNA was detected in 16 cases in frozen specimens. Of these, 15 were also positive when paraffin wax embedded material was analysed. CONCLUSIONS: This study shows that HIV proviral DNA can be detected in formalin fixed, paraffin wax embedded brain tissue by PCR. The results obtained from paraffin wax embedded specimens showed a similar degree of reliability to those from fresh frozen brain. Factors such as fixative, fixation time, and delay in performing post mortem examinations did not seem to influence PCR amplification as positive results were obtained with specimens left in fixative for up to eight months, as well as in cases where post mortem examinations had been delayed for up to four days.

Acquired Immunodeficiency Syndrome↗

A new mdr-1 encoded P-170 specific monoclonal antibody: (6/1C) on paraffin wax embedded tissue without pretreatment of sections.

AIMS: The generation and characterisation of a monoclonal antibody that specifically recognises the mdr-1 encoded protein, P-glycoprotein (P-170), on routinely processed formalin fixed, paraffin wax embedded tissue sections. METHODS: The monoclonal antibody, designated 6/1C, was produced following a combination of in vivo and in vitro immunisation regimens in Balb/c mice with a synthetic 12 amino acid peptide that corresponds to amino acids 21-32 (believed to be intracellularly located) of P-170 and has insignificant homology with the mdr-3 encoded P-170. Antibody 6/1C was characterised by western blotting and immunocytochemistry on cytospins of paired multidrug resistant or sensitive cell lines, including mdr-1 and mdr-3 transfected cells, and by immunohistochemistry on normal and malignant formalin fixed paraffin wax embedded tissue sections. RESULTS: Antibody 6/1C showed a single band at 170 kDa on western blots of multidrug resistant cell lysates and mdr-1 transfected cell lysates that was absent on similar preparations of drug sensitive cells and mdr-3 transfected cells. Immunocytochemical studies on cytospins of multidrug resistant cells and mdr-1 transfected cells revealed strong inner plasma membrane/cytoplasmic staining. Staining was negligible on drug sensitive cells and cells transfected with the mdr-3 gene. Immunohistochemical studies on formalin fixed, paraffin wax embedded normal adult kidney, liver, and breast tissue and a range of fetal tissues exhibited staining patterns of a variety of secretory surfaces consistent with documented mdr-1 specific staining. Specific staining of malignant cells in similarly treated sections of breast tumours was seen also with antibody 6/1C. Staining on paraffin wax embedded tissue with this antibody did not require any pretreatment of tissue sections. CONCLUSIONS: This new monoclonal antibody, chosen for its specificity with the mdr-1 encoded P-170 and its reactivity on routinely fixed paraffin wax embedded tissue samples without pretreatment, appears to be useful for the investigation of P-170 in archival material. It is especially useful for retrospective studies on pretreatment and post-treatment tissue sections, and could help establish when and how rapidly mdr-1 associated drug resistance develops during chemotherapeutic regimens. Immunohistochemical assessment of P-170 expression in many cancers has potential for diagnostic purposes and may influence the choice of chemotherapeutic drugs used in the treatment of refractory tumours.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Immunohistochemical detection of P-glycoprotein in normal and malignant tissues: a comparative study of three monoclonal antibodies, JSB-1, C 219 and 265/F4, against different epitopes using frozen and paraffin tissue sections.

In this study, the reactivity of three different monoclonal antibodies (MAbs) against the multiple-drug resistance (MDR)-related P-glycoprotein (P-170) were compared with each other using a collection of frozen and paraffin-embedded tumors, normal tissues and metastatic cells of malignant pleural and peritoneal effusions. The MAbs JSB-1, C 219 and 265/F4 were used in an indirect immunoperoxidase technique on frozen material. In addition, MAb C 219 was used on formalin-fixed, paraffin-embedded material from the same tumors, of which frozen sections were studied, and in a retrospective study C 219 was tested on paraffin blocks of the primary tumors that were responsible for the malignant effusions. The results show different staining patterns for all three MAbs to some extent. Results in frozen and paraffin sections obtained with MAb C 219 were comparable. MAb C 219 performs well both in frozen and formalin-fixed, paraffin-embedded material, making it a useful candidate for application in routine laboratory analysis. The retrospective analysis did not show consistency of P-170 expression in the same patients. This leads to the hypothesis that the actual status of P-170 expression in recurrent disease should be obtained before continuing or modifying chemotherapy. Clinical studies aimed at the correlation of immunohistochemistry with therapy response have to evaluate the relevance of P-170 expression in drug resistance of primary and metastatic tumors.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Epitopes of components of the plasminogen activation system are re-exposed in formalin-fixed paraffin sections by different retrieval techniques.

We present a systematic analysis of the sensitivity and specificity of immunohistochemical stainings for components of the plasminogen activation system, i.e., uPA, tPA, PAI-1, PAI-2, and uPAR, on routinely processed (formalin-fixed, paraffin-embedded) tissues. Five to nine antibodies per component were tested and the influence of different antigen retrieval regimens on immunoreactivity was investigated. We studied six different microwave-mediated pretreatments and two pretreatments by proteolytic digestion. First, positive and negative control tissues were stained. Then, frozen and paraffin sections from the same cancer lesions were stained after specific modes of pretreatment and with selected antibodies. For each component, one or a few of the tested Abs gave optimal staining on paraffin sections when combined with a particular tissue pretreatment. For PAI-1, and to a lesser degree also for tPA, an underrepresentation of stromal cell staining in paraffin material was found, whereas tumor cells showed good staining. For uPA, PAI-2, and uPAR, consistent staining results were obtained on paraffin sections.

Animals↗

Lectin histochemistry of glycolipid storage diseases on frozen and paraffin-embedded tissue sections.

Lectin histochemical studies were performed on frozen and paraffin-embedded brain tissue sections from six cases of galactosylceramide lipidosis (i.e., globoid cell leukodystrophy, or Krabbe's disease) in Twitcher mice and one case of canine infantile GM1-gangliosidosis. The globoid cells in Krabbe's disease stained with Ricinus communis agglutinin-I (RCA-I), peanut agglutinin (PNA), and Bandeirea simplicifolia agglutinin-I (BS-I) in frozen sections. However, paraffin sections and frozen sections pretreated with chloroform-methanol or xylene, from the same animals, stained with Concanavlia ensiformis agglutinin (ConA), wheat germ agglutinin (WGA), and succinylated-WGA (S-WGA), in addition to staining with RCA-I, PNA, and BS-I. The affected neurons of canine infantile GM1-gangliosidosis stained only with RCA-I in frozen sections. In paraffin sections, however, these cells were negative with RCA-I but positive with BS-I, ConA, Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA) and Ulex europaeus agglutinin (UEA-I) in paraffin sections. These results indicate that in paraffin processing of glycolipid storage disease tissue, some lectin receptors are lost and others are unmasked. The retained receptors can be stained with specific lectins and could serve as markers to characterize and differentiate among the various glycolipid storage diseases.

Animals↗

Fixation, processing, and immunochemical reagent effects on preservation of T-lymphocyte surface membrane antigens in paraffin-embedded tissue.

Fixatives, fixation additives, paraffin processing reagents, and immunochemical reagents were investigated for effects on preservation of T-lymphocyte surface membrane antigens CD3, CD4, and CD8 in human tonsil. Individual reagent effects were assessed in frozen sections by use of monoclonal antibodies and this information was used to optimize T-cell immunostaining in paraffin sections. Harmful factors were fixation delay, fixation at acid pH, fixation and processing at temperatures above 4 degrees C, hot paraffin wax, proteolytic enzymes, methanolic hydrogen peroxide, Triton X-100, and prolonged iodine treatment. Optimal T-cell demonstration in paraffin sections followed tissue fixation in periodate-lysine-paraformaldehyde dichromate at 4 degrees C, pH 7.5; processing through isopropanol, then xylene or chloroform, at 4 degrees C; and embedding in low melting point wax at 45-50 degrees C. Graded antigen stability occurred: CD3 most stable, CD8 least, and CD4 intermediate. CD4 and CD8 antigen preservation in paraffin sections required critical optimal tissue handling. CD3 was more stable and was also demonstrated in tissue fixed in commercial formalin, glutaraldehyde, and Bouin's fluid when fixation and processing conditions were optimized for pH and temperature. Of the fixation additives studied, polyethylene glycol and several potassium and magnesium salts enhanced immunostaining, whereas calcium chloride and lidocaine were deleterious.

Antigens, Differentiation, T-Lymphocyte↗

Detection of angiotensin-converting enzyme gene insertion/deletion polymorphism from paraffin-embedded tissues: the Hisayama study.

Previous studies have suggested that archival materials from formalin-fixed paraffin-embedded blocks are unsuitable for most molecular techniques because the extracted DNA can be severely degraded. Therefore, the present study was designed to investigate the accuracy of genotyping for the insertion (I)/deletion (D) polymorphism of the angiotensin-converting enzyme (ACE) gene from paraffin-embedded tissues of autopsy cases from Hisayama Town, Japan. The genotype was determined using the double polymerase chain reaction method and to test the accuracy of the method, the polymorphism was investigated using paraffin-embedded tissues from 18 cases whose ACE genotypes (6 cases for each genotype) were known in advance from analysis of fresh-frozen tissue samples. Genotyping using paraffin-embedded tissues was then determined for 968 autopsy subjects. The genotype could be determined in 16 of the 18 test samples (88.9%) and there was no discrepancy with the results obtained from the fresh-frozen tissues. Of the 968 autopsy cases, the frequency of the DD, ID, and II genotypes was 12.4%, 47.3%, and 40.3%, respectively, a distribution that did not deviate from the Hardy-Weinberg equilibrium (chi(22df )= 0.67, p=0.72). These findings suggest the accuracy of the present method of ACE genotyping from paraffin-embedded tissues.

Autopsy↗

The effect of fixatives and paraffin embedding on the histochemical reactivity of a monoclonal antibody against human type IV collagen (JK-199).

A new monoclonal antibody (JK-199) was found to react with basement membranes on paraffin-embedded tissue sections without prior enzyme digestion. JK-199 was shown to react with isolated type IV collagen treated by any of four different fixatives--PLP, 4% formalin, modified Zamboni's (0.2% picric acid, 4% paraformaldehyde in 0.1 M phosphate buffer, pH 7.4) or Bouin's--applied for 6 h at room temperature and incubated at 60 degrees C for 30 min to simulate routine tissue processing. None of the fixatives was able to alter the reactivity of JK-199 with isolated type IV collagen. In the human placenta, specific and intense staining of basement membranes was demonstrated on paraffin sections fixed with any of the four fixatives. In human skin, basement membranes were fully demonstrated on paraffin sections fixed by PLP fixative or by 4% formalin, but only partially on sections fixed by picric acid-containing fixatives. Optimal results, i.e., with the least non-specific or incomplete staining, were obtained on PLP-fixed paraffin-embedded tissues. In PLP-fixed paraffin sections of the kidney, skeletal muscle, and small intestine, all basement membranes were stained intensely by this antibody (JK-199) at the expected locations. The results indicate that JK-199 may be widely applicable for the analysis of basement membrane kinetics, including developmental processes or pathological conditions.

Antibodies, Monoclonal↗

The suitability of DNA extracted from formalin-fixed, paraffin-embedded tissues for double differential polymerase chain reaction analysis.

Formalin-fixed, paraffin-embedded (FFPE) tissues are one of the popular sources of diagnostic materials, the easiest to store and transport. They are often used as the source of nucleic acids for retrospective molecular analyses based on DNA amplification by polymerase chain reaction (PCR). However, it is known that nucleic acids from paraffin-embedded tissues are much worse templates than those recovered from fresh tissues. It is exceptionally important in a quantitative analysis, including double differential PCR (ddPCR). Therefore, a pilot study comparing quantity and quality of DNA extracted with various paraffin removal and DNA isolation procedures from FFPE tissues was conducted. Furthermore, the suitability of DNA isolated with optimized procedure for the assessment of erbB-2 average gene copy number (AGCN) was checked. Specimens for comparison of extraction and isolation procedures were generated from the same human normal thyroid tissue embedded in paraffin to eliminate variabilities in tissue processing and sample size. Three procedures of paraffin removal and three procedures of DNA extraction from deparaffinized tissue were compared. Only one procedure provided DNA, which was efficiently amplified in ddPCR. The material obtained with this optimized procedure was used to check the precision of ddPCR by evaluation of AGCN of erbB-2 oncogene. Low variability of obtained results close to expected AGCN value (AGCN=1) indicates high reproducibility of the method, as well as its high accuracy, if the normal value of erbB-2 AGCN in the examined tissue is assumed.

DNA↗

[The squash technique for silver staining of argyrophilic nucleolar organizer regions on bladder tumors: comparison with paraffin embedded sections].

We examined nucleolar organizer region (NOR) indices on 13 bladder tumors on both squash-prepared specimens and paraffin embedded specimens stained by silver-colloid method. It was noted that; 1. The nuclear size was enlarged by squashing, 2. Aggregated NOR dots were dispersed, 3. Uniformity of microscopic phase of the dots was obtained, 4. Squash specimens had more precise countabilities than the paraffin embedded sections for avoidance of nuclear resection. NOR indices (mean +/- S.D.) of those bladder tumors on squash-preparation and paraffin section were 8.64 +/- 4.32 and 6.13 +/- 1.58, respectively, and the former showed good correlation with the tumor stage. When we prepare the squashed specimen from the surgically resected bladder tumor tissue, embedding and sectioning processes which are inevitable for preparation of paraffin embedded section, could be eliminated. Thus, squash-smear technique was considered to be better than the method using paraffin embedded section on the point of shorter duration of examination and accurate countability of the NOR dots.

Aged↗

Molecular pathology of paraffin-embedded tissue. Current clinical applications.

Molecular biology techniques have been adapted to analyze paraffin-embedded tissues, expanding their potential clinical utility. The isolation of intact nucleic acids from tissue blocks is fundamental to the molecular pathology of paraffin-embedded tissues. In vitro amplification with the polymerase chain reaction (PCR) promises to be the most useful means of retrospective analysis since it can be performed successfully on DNA that has partially degraded during fixation, paraffin embedding, and the extraction process. Four clinical situations in which DNA analysis of paraffin-embedded tissues can be helpful are: (a) gene rearrangement analysis in lymphoproliferative disorders, where fresh tissue has not been obtained at the time of surgery; (b) identification of infectious agents, particularly viruses; (c) genetic testing of families with a putative inherited disease where the affected member has died; and (d) specimen identification. The PCR and other techniques of genetic analysis are powerful in sensitivity and specificity when performed and interpreted with appropriate precautions and controls. DNA analysis of paraffin-embedded tissues will likely become a fixed part of the future pathologist's diagnostic armamentarium.

DNA↗

Polymerase chain reaction/sequencing analysis of ras mutations in paraffin-embedded tissues as compared with 3T3 transfection and polymerase chain reaction/sequencing of frozen tumor deoxyribonucleic acids.

The efficiency of detection of H- and K-ras mutations in 27 CD-1 mouse liver tumors by direct sequencing of polymerase chain reaction (PCR)-amplified DNA isolated from formalin-fixed and paraffin-embedded tissues was compared with that after assay by both NIH 3T3 transfection (followed by sequencing of amplified transformant DNA) and direct sequencing of PCR-amplified DNA isolated from frozen tumors. Some tumor samples were chosen for comparison because they contained ras mutations that were detected by either NIH 3T3 transfection or sequencing of PCR-amplified DNA derived from frozen tumors, but were not detected by both techniques. The efficiency of detecting K-ras mutations was similar for sequencing of amplified fragments derived from both paraffin-embedded tissues and from frozen tumors. However, these two techniques differed in their efficacy for detection of H-ras codon 61 mutations. Furthermore, this difference appeared to be mutation-specific: the sequencing of amplified products from paraffin-embedded tumor tissues allowed increased detection of CAA to AAA mutations but decreased detection of CAA to CTA mutations relative to sequencing of amplified fragments derived from frozen tumor DNA. Direct sequencing of PCR products from paraffin-embedded sections was more sensitive than NIH 3T3 transfection for detection of activated K-ras genes containing codon 13 mutations but less sensitive for detection of activated H-ras genes containing codon 61 mutations. In summary, direct sequencing of amplified DNA from either frozen tumors or formalin-fixed, paraffin-embedded tissues can be more sensitive than NIH 3T3 transfection for detection of codon 13-activated K-ras genes. However, it appears to be less sensitive than NIH 3T3 transfection for detection of certain activating H-ras mutations. Depending upon the questions being asked of the data, each of the methods can provide useful information about ras gene mutations in tumor samples. The apparent differences in sensitivities between the methods is not yet understood, but such differences should be considered in the analysis of data obtained when only one method is used.

3T3 Cells↗

DNA content in fresh versus paraffin-embedded tissue. Flow cytometric analysis of 100 tumors.

DNA ploidy analysis was determined on 100 consecutive tumors from a wide variety of sites using both fresh and paraffin-embedded tissue on the same specimen. The correlation coefficient (r) value between the methods was 0.85. Aneuploidy was detected by both methods in 51/100 (51%) of the cases. Fresh tissue analysis yielded 10 additional cases (overall 61% aneuploidy) not detected on corresponding paraffin-embedded sections, whereas paraffin-embedded analysis detected 4 additional cases (overall 55% aneuploidy) not revealed by fresh tissue analysis. Fresh tissue analysis produced lower coefficients of variation and resulted in a cleaner preparation with less cellular debris. Fresh tissue analysis was also superior to paraffin for the detection of hypodiploid, near-diploid and multiple peaks. Analysis of paraffin-embedded material allows examination of archival tissue and provides a more rapid means of long-term follow-up and statistical correlations for prognostic studies. Although the overall correlation of both methodologies for DNA analysis showed a minimal variation in results, in our experience fresh tissue analysis has an advantage and is preferable, when available, for ploidy analysis.

Cell Separation↗

[Detection of cyclin D1 mRNA by reverse transcription-polymerase chain reaction in paraffin-embedded tissues and its diagnostic significance for mantle cell lymphoma].

OBJECTIVE: To investigate the feasibility of detecting cyclin D1 mRNA in paraffin-embedded tissues by reverse transcriptase polymerase chain reaction (RT-PCR) and competitive RT-PCR and its diagnostic and differential diagnostic significance for mantle cell lymphoma (MCL). METHODS: Paraffin-embedded samples of 36 cases of MCL, 71 cases of other small B-cell lymphomas and 20 cases of lymphoid reactive hyperplasia as control group were retrieved from archival materials. Cyclin D1 protein and its mRNA was detected by EnVision and RT-PCR and competitive RT-PCR in all samples. House-keeping gene PGK was choosen as internal control. RESULTS: (1) Cyclin D1 protein was expressed in 27 of the 38 MCL (71.1%). No cyclin D1 expression was found in the control group. (2) PGK was detected in 103 of the 116 cases (88.8%) and also detected in 34 of 36 MCL cases (94.7%). (3) cyclin D1 mRNA was detected in 34 nodal mantle cell lymphoma cases by RT-PCR in paraffin-embedded tissues. The positive rate of cyclin D1 mRNA was 94.4% in mantle cell lymphomas after exclusion of the 2 cases which were negative for both cyclin D1 mRNA and PGK. cyclin D1 mRNA was not detected in other nodal small B-cell lymphomas or lymphoid reactive hyperplasia, except 1 case of B-SLL. Sequencing analysis showed that sequences were identical to cyclin D1. (4) Cyclin D1 mRNA overexpression was detected in 27 cases of nodal mantle cell lymphoma by competitive RT-PCR in paraffin-embedded tissues. The positive rate of cyclin D1 mRNA overexpression was 75.0% in mantle cell lymphomas after exclusion of 2 cases which were negative for both cyclin D1 mRNA and PGK. cyclin D1 mRNA overexpression was not detected in other nodal small B-cell lymphomas or lymphoid reactive hyperplasia. CONCLUSION: RT-PCR and competitive RT-PCR detection of cyclin D1 mRNA overexpression could be used for the diagnosis and differential diagnosis of mantle cell lymphoma in paraffin-embedded blocks.

Cyclin D1↗

[Immunocytochemical staining of estrogen receptor in conventional formalin-fixed paraffin sections in human breast cancer].

Immunocytochemical staining for estrogen receptor (ER) was examined in conventional formalin-fixed paraffin sections in 63 patients with breast cancer. The ER staining was performed by avidin-biotin peroxidase complex method (ABC) using monoclonal antibody against ER (H222). The ER stainability in formalin-fixed paraffin sections was compared with the levels of ER measuring dextran-coated charcoal (DCC) method, and with the stainability of ER in frozen sections. ER positive rates of paraffin sections and frozen sections were 52%, and 65% respectively. ER positive level of DCC method was seen in 62 percent of the cases. Results of ER staining in paraffin sections correlated well to those of DCC method and to those of ER staining in frozen sections. In paraffin sections as well as in frozen sections, ER staining was located at the nuclei of cancer cells. Furthermore, the variety that this method for ER can be used for retrospective studies of ER on stored blocks of breast cancer.

Adult↗

Lectin binding patterns of the human cornea. Comparison of frozen and paraffin sections.

Twelve FITC-conjugated lectins were used to establish a reaction pattern with cellular and noncellular components in fresh-frozen and formalin-fixed paraffin sections of 11 normal human corneas. In frozen sections the epithelium demonstrated the most active lectin staining; keratocytes and endothelium stained to a lesser degree. Of the noncellular components, the epithelial basement membrane and Descemet's membrane of some of the tissues were stained most by Phasolus vulgaris agglutinin (PHA), Pisum sativum agglutinin (PSA), Concanavalin A (Con-A), and Sopora japonica agglutinin (SJA). None of the lectins stained Bowman's layer or the stromal matrix. Keratocytes in paraffin sections stained the most compared with the epithelium and endothelium. In paraffin sections, the epithelial basement membrane and Bowman's layer of some of the tissue sections were stained by Con-A, Ricinus cummuni agglutinin 120 (RCA-120), Banderiraea simplicifolia lectin (BSL-I), PHA, and wheat germ agglutinin (WGA). From this study, it was observed that the reactivity of lectins to the cellular components in paraffin-embedded sections was less pronounced than in frozen sections. Sensitivity of lectin binding was considerably enhanced by the proteolytic enzyme digestion of paraffin sections.

Adult↗