scholarly journals The ELF-97 Alkaline Phosphatase Substrate Provides a Bright, Photostable, Fluorescent Signal Amplification Method for FISH

1997 ◽  
Vol 45 (3) ◽  
pp. 345-357 ◽  
Author(s):  
Violette B. Paragas ◽  
Yu-Zhong Zhang ◽  
Richard P. Haugland ◽  
Victoria L. Singer
Keyword(s):  
Alkaline Phosphatase ◽  
Cultured Cells ◽  
Mdck Cells ◽  
Blot Hybridization ◽  
Stokes Shift ◽  
Southern Blot Hybridization ◽  
Zebrafish Embryos ◽  
Tissue Sections ◽  
Whole Mount ◽  
Phosphatase Substrate

We used the ELF-97 (Enzyme-Labeled Fluorescence) phosphatase substrate, 2-(5'-chloro-2-phosphoryloxyphenyl)-6-chloro-4(3H)-quinazolinone, with alkaline phosphatase conjugates of streptavidin and appropriate antibodies to amplify signals from biotinylated and haptenylated hybridization probes. The dephosphorylated product, ELF-97 alcohol, is a bright yellow-green fluorescent precipitate optimally excited at ∼360 nm, with emission centered at ∼530 nm. This large Stokes shift allows ELF-97 signals to be easily distinguished from sample autofluorescence and signals arising from counterstains or other fluorophores. The ELF-97 precipitate was extremely photostable compared to fluorescein, allowing multiple photographic exposures of samples without significant signal intensity loss. For RNA in situ hybridization, labeling was specific and localized well to targets in cultured cells, tissue sections, and whole-mount zebrafish embryos. ELF-97 signals developed in seconds to minutes and were easily distinguished from pigmented tissues or cells, unlike those obtained using colorimetric substrates. We used the substrate with singly biotinylated short oligonucleotides to detect actin mRNA in MDCK cells and actin and β-galactosidase mRNA in LacZ+ mouse fibroblasts. We also used a biotinylated cDNA, complementary to the mRNA encoded by the constant region of the T-cell receptor β-chain, to specifically identify T-cells in mouse lymph node tissue sections. With digoxigenin-labeled probes, we detected several developmentally expressed mRNAs in whole-mount zebrafish embryos. Hybridization to centromere repeat regions in human metaphase and interphase chromosomes was also detected; ELF-97 signals were manyfold brighter than signals obtained with fluorescein conjugates. Finally, Southern blot hybridization using singly labeled oligonucleotide probes yielded a sensitivity similar to that obtained with radioactivity. (J Histochem Cytochem 45:345–357, 1997)

scholarly journals Use of a new fluorogenic phosphatase substrate in immunohistochemical applications.

1995 ◽  
Vol 43 (1) ◽  
pp. 77-83 ◽  
Author(s):  
K D Larison ◽  
R BreMiller ◽  
K S Wells ◽  
I Clements ◽  
R P Haugland
Keyword(s):  
Alkaline Phosphatase ◽  
Stokes Shift ◽  
High Magnification ◽  
Adult Zebrafish ◽  
Large Stokes Shift ◽  
Retinal Tissue ◽  
Bright Yellow ◽  
Immunohistochemical Techniques ◽  
Phosphatase Substrate

We used the phosphatase substrate 2-(5'-chloro-2'-phosphoryloxyphenyl)-6- chloro-4-[3H]-quinazolinone, with standard alkaline phosphatase-mediated immunohistochemical techniques, to visualize a number of antibodies that bind to adult zebrafish retinal tissue. This compound, known as the ELF (enzyme-labeled-fluorescence) phosphatase substrate, produces a precipitate that fluoresces at approximately 500-580 nm (bright yellow-green). We show that the precipitated product from the ELF phosphatase substrate has a number of characteristics that make it superior to fluorescein-labeled secondary reagents. The staining produced with the ELF substrate is much more photostable than that produced by fluorescein-labeled secondary reagents, thus allowing time to examine, focus, and photograph the ELF-labeled tissue under high magnification. Moreover, the ELF precipitate exhibits a Stokes shift of greater than 100 nm, a characteristic that has enabled us to overcome the problem of distinguishing signal from background in this autofluorescent tissue. In addition, we show that the ELF product's large Stokes shift makes the ELF substrate ideal for multicolor applications.

Analysis of genetic polymorphisms affecting the four phospholipase C (plc) genes in Mycobacterium tuberculosis complex clinical isolates

Microbiology ◽  
2004 ◽  
Vol 150 (4) ◽  
pp. 967-978 ◽  
Author(s):  
C. Viana-Niero ◽  
P. E. de Haas ◽  
D. van Soolingen ◽  
S. C. Leão
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Phospholipase C ◽  
Genetic Polymorphisms ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Clinical Isolates ◽  
Significant Similarity ◽  
Genomic Deletions ◽  
Genes Encoding ◽  
Mycobacterium Africanum

The Mycobacterium tuberculosis genome contains four highly related genes which present significant similarity to Pseudomonas aeruginosa genes encoding phospholipase C enzymes. Three of these genes, plcA, plcB and plcC, are organized in tandem (locus plcABC). The fourth gene, plcD, is located in a different region. This study investigates variations in plcABC and plcD genes in clinical isolates of M. tuberculosis, Mycobacterium africanum and ‘Mycobacterium canettii’. Genetic polymorphisms were examined by PCR, Southern blot hybridization, sequence analysis and RT-PCR. Seven M. tuberculosis isolates contain insertions of IS6110 elements within plcA, plcC or plcD. In 19 of 25 M. tuberculosis isolates examined, genomic deletions were identified, resulting in loss of parts of genes or complete genes from the plcABC and/or plcD loci. Partial plcD deletion was observed in one M. africanum isolate. In each case, deletions were associated with the presence of a copy of the IS6110 element and in all occurrences IS6110 was transposed in the same orientation. A mechanism of deletion resulting from homologous recombination of two copies of IS6110 was recognized in a group of genetically related M. tuberculosis isolates. Five M. tuberculosis isolates presented major polymorphisms in the plcABC and plcD regions, along with loss of expression competence that affected all four plc genes. Phospholipase C is a well-known bacterial virulence factor. The precise role of phospholipase C in the pathogenicity of M. tuberculosis is unknown, but considering the potential importance that the plc genes may have in the virulence of the tubercle bacillus, the study of isolates cultured from patients with active tuberculosis bearing genetic variations affecting these genes may provide insights into the significance of phospholipase C enzymes for tuberculosis pathogenicity.

scholarly journals Impact of Heterogeneity within Cultured Cells on Bacterial Invasion: Analysis of Pseudomonas aeruginosa andSalmonella enterica Serovar Typhi Entry into MDCK cells by Using a Green Fluorescent Protein-Labelled Cystic Fibrosis Transmembrane Conductance Regulator Receptor

2000 ◽  
Vol 68 (2) ◽  
pp. 861-870 ◽  
Author(s):  
A. Alev Gerçeker ◽  
Tanweer Zaidi ◽  
Peter Marks ◽  
David E. Golan ◽  
Gerald B. Pier
Keyword(s):  
Epithelial Cells ◽  
Protein Expression ◽  
Fluorescent Protein ◽  
Cultured Cells ◽  
Mdck Cells ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Bacterial Uptake ◽  
Cftr Protein ◽  
Green Fluorescent

ABSTRACT The cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride ion channel that also serves as a receptor for entry ofPseudomonas aeruginosa and Salmonella entericaserovar Typhi into epithelial cells. To evaluate heterogeneity in CFTR protein expression in cultured cells and the effect of heterogeneity on internalization of different P. aeruginosa and serovar Typhi strains, we used two-color flow cytometry and confocal laser microscopy to study bacterial uptake by Madin-Darby canine kidney (MDCK) type I epithelial cells stably expressing a green fluorescent protein (GFP)-CFTR fusion construct (MDCK–GFP-CFTR cells). We found a strong correlation between cell size and GFP-CFTR protein expression, with 60 to 70% of cells expressing low levels of GFP-CFTR protein, 20 to 30% expressing intermediate levels, and <10% expressing high levels. The cells were sorted into low-, intermediate-, or high-level producers of CFTR protein; in vitro growth of each sorted population yielded the same distribution of CFTR protein expression as that in the original population. Cells expressing either low or high levels of CFTR protein internalized bacteria poorly; maximal bacterial uptake occurred in the cells expressing intermediate levels of CFTR protein. Treatment of MDCK cells with sodium butyrate markedly enhanced the production of CFTR protein without increasing cell size; butyrate treatment also increased the proportion of cells with internalized bacteria. However, there were fewer bacteria per butyrate-treated cell and, for P. aeruginosa, there was an overall decrease in the total level of bacterial uptake. The most highly ingested bacterial strains were internalized by fewer total MDCK–GFP-CFTR cells, indicating preferential bacterial uptake by a minority of epithelial cells within a given culture. Confocal fluorescence microscopy showed that P. aeruginosa and serovar Typhi induced cytoplasmic accumulation of CFTR protein close to the plasma membrane where the bacteria were adherent. These results show that within a population of MDCK–GFP-CFTR cells, there are cells with markedly different abilities to ingest bacteria via CFTR, the majority of the P. aeruginosa and serovar Typhi cells are ingested by the one-fourth to one-third of the cells that exhibit an intermediate size and level of CFTR protein expression, and overexpression of the CFTR receptor does not increase total bacterial uptake but rather allows more epithelial cells to ingest fewer total bacteria.

Repair and recombination of X-irradiated plasmids in Xenopus laevis oocytes

1990 ◽  
Vol 10 (11) ◽  
pp. 5849-5856
Author(s):  
S E Sweigert ◽  
D Carroll
Keyword(s):  
Homologous Recombination ◽  
Xenopus Laevis ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Coli Strain ◽  
Xenopus Laevis Oocytes ◽  
X Rays ◽  
Strand Breaks ◽  
X Ray ◽  
Dna Strand

Plasmid DNA substrates were X-irradiated and injected into the nuclei of Xenopus laevis oocytes. After incubation for 20 h, DNA was recovered from the oocytes and analyzed simultaneously for repair and for intermolecular homologous recombination by electrophoresis and bacterial transformation. Oocyte-mediated repair of DNA strand breaks was observed with both methods. Using a repair-deficient mutant Escherichia coli strain and its repair-proficient parent as hosts for the transformation assay, we also demonstrated that oocytes repaired oxidative-type DNA base damage induced by X-rays. X-irradiation of a circular DNA stimulated its potential to recombine with a homologous linear partner. Recombination products were detected directly by Southern blot hybridization and as bacterial transformant clones expressing two antibiotic resistance markers originally carried separately on the two substrates. The increase in recombination was dependent on X-ray dose. There is some suggestion that lesions other than double-strand breaks contribute to the stimulation of oocyte-mediated homologous recombination. In summary, oocytes have considerable capacity to repair X-ray-induced damage, and some X-ray lesions stimulate homologous recombination in these cells.

Tandem arrangement of tubulin genes in the protozoan parasite Leishmania enriettii

1983 ◽  
Vol 3 (6) ◽  
pp. 1070-1076
Author(s):  
S M Landfear ◽  
D McMahon-Pratt ◽  
D F Wirth
Keyword(s):  
Tandem Repeat ◽  
Blot Hybridization ◽  
Protozoan Parasite ◽  
Southern Blot Hybridization ◽  
Beta Tubulin ◽  
Developmentally Regulated ◽  
Alpha Tubulin ◽  
Tubulin Genes ◽  
Southern Blot Hybridization Analysis ◽  
Leishmania Enriettii

The arrangement of developmentally regulated alpha- and beta-tubulin genes has been studied in the parasitic protozoan Leishmania enriettii by using Southern blot hybridization analysis. The alpha-tubulin genes occur in a tandem repeat whose monomeric unit may be represented by a 2-kilobase PstI fragment. Similarly, the beta-tubulin genes probably occur in a separate tandem repeat consisting of approximately 4-kilobase units unlinked to the alpha-tubulin repeats.

Presence of Human Herpesvirus 8 DNA Sequences in Renal Transplantation-Associated Pleural Kaposi Sarcoma

1999 ◽  
Vol 123 (12) ◽  
pp. 1269-1273
Author(s):  
J. Javier Gómez-Román ◽  
J. Gonzalo Ocejo-Vinyals ◽  
Pablo Sánchez-Velasco ◽  
Francisco Leyva-Cobián ◽  
J. Fernando Val-Bernal
Keyword(s):  
Kidney Transplantation ◽  
Pleural Effusion ◽  
Dna Sequences ◽  
Blot Hybridization ◽  
Human Herpesvirus ◽  
Kaposi Sarcoma ◽  
Southern Blot Hybridization ◽  
Pulmonary Involvement ◽  
Human Herpesvirus 8 ◽  
Herpesvirus 8

Abstract Objective.—To describe one case of symptomatic skin and pleural Kaposi sarcoma (KS) associated with kidney transplantation. Diagnosis was supported by morphologic study and human herpesvirus 8 (HHV-8) detection in both tissues. Pulmonary involvement was not present. Design.—The presence of HHV-8 DNA sequences was proved using polymerase chain reaction (PCR), Southern blot hybridization, and in situ hybridization. Setting.—Human herpesvirus 8 is found in most KS from patients with and without the acquired immunodeficiency syndrome. Clinically significant pulmonary infiltration by KS is diagnosed uncommonly antemortem, and pleural disease is exceptional. Patient.—A 49-year-old man who had renal transplant with immunosuppressive therapy (tacrolimus and prednisone) and developed a cutaneous KS. A pleural effusion appeared without pulmonary involvement. Both lesions disappeared when immunosuppressive drugs were suspended. Later, the pleural effusion and the cutaneous lesions reappeared. Pleural biopsy specimens showed KS infiltration. Outcome.—The patient refused treatment and was lost to follow-up. Results.—The skin and pleural biopsies showed a proliferation of spindle-shaped cells positive for CD34. The HHV-8 sequences were detected by nested PCR. No amplification was detected in uninvolved skin from the patient or in peripheral blood mononuclear cells from 10 healthy individuals used as controls. The Southern blot hybridization confirmed these results. Conclusions.—To our knowledge, this is the first report of HHV-8 in symptomatic pleural KS, which was probably associated with immunosuppression after kidney transplantation. The demonstration of HHV-8 DNA in biopsy material in the appropriate cells could be diagnostic when the morphologic setting is consistent with KS.

Renal expression of osteopontin and alkaline phosphatase correlates with BUN levels in aged rats

1995 ◽  
Vol 269 (3) ◽  
pp. F398-F404
Author(s):  
C. T. Liang ◽  
J. Barnes
Keyword(s):  
Alkaline Phosphatase ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Blot Hybridization ◽  
Northern Blot Hybridization ◽  
Tgf Beta ◽  
Young Rats ◽  
Beta Actin ◽  
Old Rats ◽  
Renal Expression

Renal expression of alkaline phosphatase (AP) and osteopontin (OP) in rats of different age was examined. Northern blot hybridization showed that AP mRNA was reduced moderately, whereas OP mRNA was stimulated drastically in old rats. Dot-blot quantitation analysis showed that AP mRNA decreased 30% in 24-compared with 6-mo-old rats. In contrast, OP mRNA increased 3.1- and 9.1-fold, respectively, in 12- and 24-mo-old rats. beta-Actin mRNA did not change with age. Blood urea nitrogen (BUN) increased 47 and 187% in 12- and 24-mo-old rats, respectively. Correlation analysis showed that BUN correlated negatively with AP mRNA and positively with OP mRNA. No correlation was observed with beta-actin. The expression of these markers was also examined in femurs. AP and OP mRNAs were marginally reduced in old bones. To test whether the correlation also exists in other types of renal insufficiency, we examined these parameters in young rats infused with parathyroid hormone (PTH). BUN was elevated 3.5-fold, whereas AP mRNA decreased 48%, and OP mRNA increased 15.3-fold in kidneys of PTH-treated rats. To elucidate the possible mechanisms that lead to the overexpression of OP in kidney, we examined the expression of transforming growth factor-beta 1 (TGF-beta 1) mRNA. No significant differences in TGF-beta 1 expression were observed between young and old rats and control and PTH-treated young rats. Changes in the expression of OP were also visualized by immunostaining of renal sections. Alterations in the levels of OP and AP were validated by Western blot analysis and enzyme assay of homogenate, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

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