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At least 721 records · Page 40Linked to original sources
PubMed2000

Evaluation of the role of mitotic instability in karyotypically normal men with oligozoospermia.

OBJECTIVE: To estimate the incidence of sex chromosome aneuploidies in the somatic cells of karyotypically normal infertile men and fertile donors. DESIGN: A prospective, two-phase, controlled study. SETTING: Reproductive medicine and medical genetics units of a teaching hospital. PATIENT(S): Ten patients with oligozoospermia and 10 sperm donors with proved fertility, all with a normal karyotype 46 XY. INTERVENTION(S): Multicolor fluorescence in situ hybridization (FISH) of peripheral blood lymphocytes using a probe cocktail containing the alpha satellites DXZ1 for the X centromere and DYZ1 for the heterochromatic region of the long arm of the Y and the radiolabeled alpha satellite D18Z1 for chromosome 18. MAIN OUTCOME MEASURE(S): The incidence of sex chromosome aneuploidies in both groups. RESULT(S): A 13-fold increase in sex chromosome aneuploidies was observed in the somatic cells of infertile men with "unexplained" oligozoospermia compared to donors (P=.008). CONCLUSION(S): These findings provide suggestive evidence for the existence of an inherent mitotic instability in men with unexplained oligozoospermia.

Adult↗
PubMed1997

Phenotypes of B and T cells in human intestinal and mesenteric lymph.

BACKGROUND & AIMS: Cells in lymph draining the human gut have not been characterized previously. The aim of this study was to phenotype B and T cells present in microlymphatics of Peyer's pathces and in mesenteric lymph. METHODS: The studies were conducted by multicolor immunohistochemistry, flow cytometry, and immunocytochemistry. RESULTS: In decreasing order of frequency, microlymphatics in Peyer's patches contained naive T (CD3+CD45RA+ alpha 4 beta 7low) and B (sIgD+CD20+ alpha 4 beta 7low) lymphocytes, memory T (CD45RO+ alpha 4 beta 7+) and B (sIgD-CD20+ alpha 4 beta 7+) lymphocytes, and B-cell blasts (CD19+CD38high alpha 4 beta 7high). Naive cells were usually positive for L-selectin, memory cells were either positive or negative, and B-cell blasts were usually negative. Mesenteric lymph contained naive T (approximately 60%) and B (approximately 25%) lymphocytes, memory T and B lymphocytes (approximately 10%), and B-cell blasts (approximately 2%). Cytospins confirmed these results and showed, in addition, that B-cell blasts contained cytoplasmic immunoglobulin (Ig) A, IgM, or IgG in overall proportions of 5:1: < 0.5. CONCLUSIONS: Our results are similar to the phenotypes previously described in animal thoracic or mesenteric lymph. A fraction of the B cells stimulated in Peyer's patches are near terminal differentiation (contain cytoplasmic Ig) before they enter peripheral blood. Many memory cells, and most if not all B-cell blasts entering lymph show an adhesion molecule profile (alpha 4 beta 7high L-selectin low) in keeping with the presumed phenotype of lymphoid cells destined for mucosal effector sites such as the gut lamina propria.

Adult↗
PubMedDate not supplied

A study of laser photocoagulation for polypoidal choroidal vasculopathy.

PURPOSE: To evaluate the efficacy of laser photocoagulation for polypoidal choroidal vasculopathy (PCV) involving the macula. METHODS: The records of 38 patients (47 eyes) undergoing laser photocoagulation for PCV causing serosanguineous detachment involving the fovea were reviewed and the results were evaluated. Ten eyes underwent photocoagulation to induce a fusion scar covering whole lesions consisting of both abnormal vessels and polypoidal lesions. Thirty-seven eyes underwent photocoagulation for only polypoidal lesions. When serosanguineous detachment recurred, additional photocoagulation was performed, targeting the causative lesions. Photocoagulation was performed with an argon dye laser or multicolor krypton laser. Final visual acuity, macular changes at the final visit, and the number of photocoagulations were evaluated. Follow-up period after the first photocoagulation was at least 1 year. RESULTS: Of the 10 eyes undergoing photocoagulation of whole lesions, 9 showed absorption of exudate and/or blood after one photocoagulation, and maintained or improved visual acuity. Of the 37 eyes undergoing laser photocoagulation of only polypoidal lesions, 20 (54%) showed decreased visual acuity because of recurrent or persistent exudation and/or classic choroidal neovascularization or, alternatively, because of atrophy at the fovea; 32 of the 37 eyes had undergone photocoagulation at least twice or more. CONCLUSION: Photocoagulation is recommended only for whole lesions.

Aged↗
PubMed1997

Rapid sizing of polymorphic microsatellite markers by capillary array electrophoresis.

Genetic mapping and DNA sequencing projects could potentially be completed more rapidly by using capillary array electrophoresis (CAE) systems running 48-96 capillaries simultaneously. Currently, multiplex polymerase chain reaction (PCR) and multicolor fluorescent dye-labeling strategies are used to generate DNA profiles containing 18-24 genotypes per sample. By using 4-color fluorescence detection and these multiplex PCR strategies, a CAE system has the capacity to generate up to 5.5 million genotypes per year. CAE offers extremely fast, high-resolution separation of DNA and more automated sample processing than conventional systems because the labor-intensive slab-gel pouring and sample-loading steps are eliminated. We used a prototype CAE system in an ongoing linkage analysis study of inherited deafness in Mediterranean families. CA-repeat markers linked to deafness susceptibility genes on chromosomes 7, 11 and 13 were analyzed and DNA profiles generated which contain 6 markers per color. Fragment sizes of over 28,000 short tandem repeat alleles and 3200 CA-repeat alleles have been determined by CAE. An average sizing precision of +/- 0.12 base pairs (bp) for fragments up to 350 bp was realized in 1-h runs. In addition, a versatile non-denaturing matrix was used to separate DNA sizing standards, restriction digests, and multiplex PCR samples. Application of this matrix to Duchenne muscular dystrophy exon deletion screening is also described. These CAE approaches should facilitate rapid genotyping of microsatellite markers and subsequent identification of disease-causing mutations.

Base Sequence↗
PubMed2001

Cyanobacterial stabilized phycobilisomes as fluorochromes for extracellular antigen detection by flow cytometry.

Phycobilisomes are cyanobacterial photosynthetic energy transfer complexes partly composed of phycobiliproteins, proteins that are widely used as conjugable fluorochromes for flow cytometry. The brightness and photostability of phycobiliproteins suggest that intact phycobilisomes could constitute even brighter probes for fluorescence-based detection systems. Stabilized phycobilisomes have been isolated and the red-excited, far red-emitting Spirulina platensis-derived complex PBXL-3 was accessed as a fluorochrome for flow cytometric immunodetection of surface antigens on immune cells. Although the large size of intact phycobilisomes initially precluded efficient cell surface labeling, the addition of a PEG spacer arm between PBXL-3 and its conjugated avidin molecule (designated PBXL-3L) reduced the steric hindrance associated with the high molecular weight PBXL complex. PBXL-3L increased the surface labeling surface-to-noise ratio and subsequent sensitivity by several-fold over commonly used red-excited fluorochromes such as APC. Interestingly, low power laser sources (including helium-neon and red diode) were particularly efficient at exciting PBXL-3. PBXL-3 was also compatible in with other fluorochromes for multicolor flow cytometry applications. In summary, PBXL-3 was found to possess superior sensitivity and efficiency for flow cytometric immunodetection, particularly with low power laser sources.

Animals↗
PubMed2002

Versatility of merocyanine 540 for the flow cytometric detection of apoptosis in human and murine cells.

Since apoptosis plays many roles in development, immune function, and disease, there is an ongoing need to identify inexpensive and reliable fluorochromes for the quantitation of apoptosis. Merocyanine 540 (MC540) binds to the outer membrane of cells and readily fluoresces in the highly disordered membranes of apoptotic cells making them readily detectable by flow cytometry. Protocols for the effective labeling and gating of MC540br apoptotic cells are provided. For example, MC540br cells from dexamethasone (Dex) treated thymocytes were found to be equivalent in proportion to apoptotic cells noted in the propidium iodide (PI) stained and annexin-V stained populations. Sorting of the MC540br cells followed by counterstaining with PI demonstrated that these cells resided in the low DNA fluorescent or sub-G1 region and were small in size based on light scatter. Dexamethasone, etoposide, irradiation, and a calcium ionophore were used to induce cell death with equivalent numbers of apoptotic cells obtained with MC540 and PI. Moreover, apoptotic human bone marrow (BM) B cells, neutrophils, Jurkat T cells, and testicular cells could readily be identified with MC540. The latter is particularly noteworthy since some of the standard methods for identifying cell death have not worked well with human cells. The versatility of this dye is such that it was also possible to phenotypically label cells stained with MC540 to analyze apoptosis in heterogenous populations of cells. Finally, the rate of detection of apoptotic cells after treatment of thymocytes with dexamethasone at 2, 4, 6, and 8 h with MC540 was shown to be equivalent to PI and annexin-V. Taken together, the data demonstrate that when proper precautions are taken, MC540 is a reliable, versatile, and inexpensive fluorochrome that can be used to identify apoptotic cells of human or murine origin even in heterogenous populations that require multicolor labeling.

Animals↗
PubMed1998

Green- and red-fluorescent nanospheres for the detection of cell surface receptors by flow cytometry.

Fluorescent probes serve as sensitive tools for obtaining structural and functional information in cellular systems. In spite of the high sensitivity provided by fluorescent reagents, cell surface receptors expressed in low numbers often escape detection with commonly used fluorescent probes. R-Phycoerythrin (R-PE), a molecule with a very high quantum yield, is often the reagent of choice for the detection of such low abundance events. We have developed streptavidin conjugates of two highly fluorescent 35-40 nm diameter polystyrene nanospheres, the green fluorescent FluoSpheres (Ex/Em 505/515) and red fluorescent TransFluoSpheres (Ex/Em 488/645). Like R-PE, the new reagents have peak excitations near 488 nm but differ in their emission maxima; 515 nm for the green nanospheres, 645 nm for the red nanospheres and 575 nm for R-PE. Hence the nanospheres are detected by flow cytometry in channels capable of detecting green (FL1) and red (FL3) fluorescence, while R-PE is detected in channel FL2. These nanospheres were tested for the detection of the sparsely expressed epidermal growth factor receptor (EGFR) of NIH-3T3 cells and the densely expressed EGFR of A431 cells. Results indicate that the nanosphere reagents are more sensitive than fluorescein-streptavidin and at least comparable in sensitivity to R-PE-streptavidin. The simultaneous use of these nanospheres with R-PE was also studied by concurrent staining of the CD3 and CD4 receptors in JURKAT cells. Labeling of CD4 receptors with streptavidin nanospheres and CD3 receptors with the R-PE-anti-CD3 conjugate confirmed the suitability of using the new nanospheres in combination with R-PE in multicolor flow cytometry experiments. This paper thus describes the use of alternative tools with detection sensitivity comparable to that of R-PE, but detected in different channels than R-PE, permitting their simultaneous use with R-PE.

3T3 Cells↗
PubMed2000

Automated data acquisition by confocal laser scanning microscopy and image analysis of triple stained immunofluorescent leukocytes in tissue.

The aim of the study was to develop a novel system permitting automated analysis of multicolor immunofluorescence-staining of cells in solid tissues which would be comparable to the analytical capacity of flow cytometry. In the user friendly automated data acquisition and image processing system which was established, the software includes a set of pre-defined processing steps for improved object identification and can be either interactive or fully automatic. As with multi color flow cytometry, stained cells can be analyzed in a fully automated manner regardless of tissue type. The software organizes computerized sample movement, autofocus, laser readjustment, data capture and storage as well as calculation. Data are presented as histograms indicating the staining intensity and frequency of each antigen, and in dotplots with each channel plotted against the other. The calculated statistics give information about how many of the cells are single-, double- or triple-reactive and how intensely they react with the respective antibodies. Comparison of data generated by this automated fluorescence confocal laser scanning microscopy (AF-CLSM) with flow cytometry using triple stained peripheral blood lymphocytes revealed a highly significant correlation between the methods (P<0.001). A correlation was also observed when sections triple stained for anti-CD45, -CD3 and -CD8 were analyzed by AF-CLSM and the data were compared to visual/manual cell counting (P<0.01). The AF-CLSM system permits for the first time, fast (online) and reproducible analysis of immunofluorescence staining of an unlimited number of cells in tissue sections. The software, including a manual, is available for a small fee to cover the costs of printing and postage.

CD3 Complex↗
PubMed2000

Rapid detection of radiation-induced chromosomal aberrations in lymphocytes and hematopoietic progenitor cells by mFISH.

Structural chromosome aberrations (SCAs) are sensitive indicators of a preceding exposure of the hematopoietic system to ionizing radiation. Cytogenetic investigations have therefore become routine tools for an assessment of absorbed radiation doses and their biological effects after occupational exposure or radiation accidents. Due to its speed and ease of use, fluorescence in situ hybridization (FISH) with whole chromosome painting (WCP) probes has become a method of choice to visualize SCAs. Until recently, this technique was limited to a rather small number of chromosomes, which could be tested simultaneously. As a result, only a fraction of the structural aberrations present in a sample could be detected and the overall dose effect had to be calculated by extrapolation. The recent introduction of two genome-wide screening techniques in tumor research, i.e., Spectral Karyotyping (SKY) and multicolor FISH (mFISH) now allows the detection of translocations involving any two non-homologous chromosomes. The present study was prompted by our desire to bring the power of mFISH to bear for the rapid identification of radiation-induced SCAs. We chose two model systems to investigate the utility of mFISH: lymphocytes that were exposed in vitro to 3 Gy photons and single hematopoietic progenitor cell colonies isolated from a Chernobyl victim 9 years after in vivo exposure to 5.4 Sv.In lymphocytes, we found up to 15 different chromosomes involved in rearrangements indicating complex radiation effects. Stable aberrations detected in hematopoietic cell colonies, on the other hand, showed involvement of up to three different chromosomes. These results demonstrated that mFISH is a rapid and powerful approach to detect and characterize radiation-induced SCAs in the hemopoietic system. The application of mFISH is expected to result in a more detailed and, thus, more informative picture of radiation effects. Eventually, this technique will allow researchers to rapidly delineate chromosomal breakpoints and facilitate the identification of the genes involved in radiation tumorigenesis.

Adult↗
PubMed2002

Application of mFISH for the analysis of chemically-induced chromosomal aberrations: a model for the formation of triradial chromosomes.

Using a human lymphoblastoid cell line WTK-1, we applied multicolor fluorescence in situ hybridization (mFISH) technique to analyze mitomycin C (MMC)-induced chromatid exchanges, focusing especially on the triradial chromosomes. It was found that the triradial chromosomes were formed with a specific rearrangement, "recipient and donor" relationship. The exchange sites of the recipient chromosomes were on single chromatid breaks and distributed randomly throughout the interstitial, pericentromeric, and terminal regions. In counterpart, donor chromosomes exchanged on isochromatid breaks of their telomeric and/or subtelomeric regions with the single chromatid breaks of recipient chromosomes. More than 80% of the scored triradial chromosomes were formed with such rearrangements, and few acentric chromosome fragments derived from the donor chromosomes could be detected in the metaphases observed. We therefore suggest that biological mechanisms of breakages between the recipient and donor chromosomes are different: the former due to direct DNA-damage by MMC, but the latter due to indirect DNA-damage depending on telomeric specific structure/function.

Alkylating Agents↗
PubMed1997

X-ray-sensitivity of lymphocytes of aplastic- and Diamond-Blackfan-anemia patients as detected by conventional cytogenetic and chromosome painting techniques.

Frequencies of spontaneously occurring and X-ray induced, stable and unstable types of chromosome aberrations in peripheral blood lymphocytes from two groups of radiosensitive patients, i.e., aplastic anemia (AA) and Diamond-Blackfan anemia (DBA), were determined. Two types of staining methods, i.e., chromosome painting with two cocktails of chromosome-specific DNA libraries (Nos. 1, 3, X and Nos. 2, 4 and 8), as well as conventional Giemsa staining, were employed. Chromosome painting was done with single and multicolor fluorescence in situ hybridization (FISH). The frequencies of spontaneously occurring chromosome aberrations in AA and DBA patients were not significantly different from healthy individuals. Hypersensitivity to X-rays was seen both in G0 as well as in G2 phase of the cell cycle in lymphocytes from AA and DBA patients, confirming our earlier findings using micronucleus (DBA) and G2 radiosensitivity (AA) assays.

Anemia, Aplastic↗
PubMed2003

Rapid assessment of the prevalence of lower limb clinical rickets in Bangladesh.

This study attempted to measure the prevalence of lower limb clinical rickets using a rapid assessment methodology in Cox's Bazaar, a coastal district of Bangladesh. The study populations were drawn from 28 random villages representing all seven 'thanas' (subdistricts) of the district. Data were collected on 25,891 children and young people aged 1-20 years in two phases. In the first phase, 30 trained, local, non-medical people listed 490 children suffering from visible signs of any physical disability. To achieve this, they demonstrated a multicolored poster showing the features of lower limb clinical rickets to key informants in the villages. In the second phase, two teams of medically trained people (physicians), each with one male and one female, validated the above cases for rickets. They verified and validated 278 cases in five thanas. Due to inclement weather and floods, they could not visit the other two thanas. Based on these data, the adjusted prevalence rates for lower limb clinical rickets were calculated to be 931 per 100,000 population (95% confidence intervals 795-1067). The prevalence was highest (1215) in children aged 1-4 years and lowest (498) amongst 17-20 year olds. Females had lower prevalence than males. Based on the study experience, a quick investigation using a similar methodology was performed in five other districts (Sunamganj, Noakhali, Bhola, Jessore and Gaibandha), and clinical signs of lower limb rickets were found in Sunamganj and Jessore. It thus indicates that rickets may be endemic, not only in Cox's Bazaar but also in some other parts of Bangladesh. The methodology used for this study was found to be rapid, simple, replicable and inexpensive.

Adolescent↗
PubMed1995

Molecular and cytogenetic characterization of a t(1;10;21) translocation in the human papillary thyroid cancer cell line TPC-1 expressing the ret/H4 chimeric transcript.

BACKGROUND: Activation of the ret proto-oncogene by three different chromosomal rearrangements occurs in up to 25% of papillary thyroid carcinomas. We developed a rapid screening technique to detect ret rearrangements in human interphase and metaphase cells on the basis of multicolor fluorescence in situ hybridization (FISH) of locus-specific DNA probes. METHODS: DNA from individual clones representing the respective ends of a yeast artificial chromosome (YAC) contig spanning the entire ret gene locus were labeled with either digoxigenin (visualized in red) or biotin (green) and hybridized to normal human lymphocytes and the papillary thyroid cancer cell line TPC-1 expressing the ret/H4 chimeric transcript. Further detailed analysis was performed with whole chromosome painting probes and locus-specific probes (YACs, P1s, DNA repeat probes) on tumor metaphase spreads. RESULTS: Hybridization of the YACs to unrearranged ret loci in normal human lymphocyte interphase nuclei showed two yellow domains because of probe overlap. Hybridization to TPC-1 interphase nuclei showed one yellow domain, and 1 red and 1 green domain separated by a large physical distance. Further analysis of metaphase spreads revealed a complex translocation t(1;10;21)(1pter > 1q31::21q22.1 > 21qter; 10q11.2 > 10pter::1q31 > 1qter; 21pter > 21q22.1;;10q21.2 > 10q11.2::10q21.2 > 10qter) and loss of the H4 gene locus on the nontranslocated chromosome 10. CONCLUSIONS: Break point spanning probes can reliably detect ret rearrangements in interphase nuclei. Locus-specific and whole chromosome painting probes can be used to further characterize complex rearrangements by fluorescence in situ hybridization to metaphase spreads. The papillary thyroid cancer cell line TPC-1 carries the paracentric inversion 10q, inv(10)(q11.2q21) and a complex t(1; 10; 21) translocation. Deletion of the H4 gene on the chromosome 10 not involved in the t(1; 10; 21) translocation suggests lack of normal H4 expression in the TPC-1 cell line. Further studies will have to address the role of the H4 gene product in tumor genesis and progression.

Carcinoma, Papillary↗
PubMed1985

Rapid preparation of lecture slides.

When lecture slides must be prepared at a moment's notice, these methods of rapid preparation will allow you to create good quality slides. Although rush jobs are usually associated with higher costs, using these methods will keep the price per slide to a minimum. An investment must be made for the initial equipment, but the cost per slide is much less than that of slides produced by the standard methods. Type produced by typewriters or computer printers is adequate for most slides, but better slides can be produced with KroyType or Letraset letters. The KL film is preferred for reverse slides of text or line drawings, and the RPC film for production of radiographic slides. If an X-omat developer is not available, Polaroid film is a good alternative for rapid production of slides. The KL reverse slide projects best and can be colored, but RPC film produces a good positive slide of typed material. We have also photographed from a computer terminal screen using the KL film to make positive slides, the Polaroid continuous tone film for reverse slides, and Polaroid color film for color slides of material composed on a computer terminal with multicolor and graphics capabilities.

Computers↗
PubMed2000

Peroxidative degradation of selected PCB: a mechanistic study.

The enzyme-induced decomposition and biodegradation of PCB were investigated. 2,5-Dichlorobiphenyl (PCB 9) and 2,2',5,5'-tetrachlorobiphenyl (PCB 52) were used as example compounds to study efficiency and mechanism of the degradation processes. It was found that the application of horseradish peroxidase (HRP) together with defined amounts of hydrogen peroxide removed 90%, of the initial concentration of PCB 9 and 55% of the initial concentration of PCB 52 from an aqueous solution after a reaction period of 220 min. Dechlorination was observed as the initial step. Although the metabolites identified were mainly chlorinated hydroxybiphenyls, benzoic acids and non-substituted 1,1'-biphenyl, some higher chlorinated biphenyl isomers also appeared. The biodegradation of PCB 9 using the white rot fungus Trametes multicolor took about four weeks and reduction was about 80%, of the initial concentration. The metabolites produced (dichlorobenzenes, chlorophenols and alkylated benzenes) were not quite the same as those observed upon incubation with HRP.

Benzoic Acid↗
PubMed1996

Multiparameter fluorescence imaging microscopy: reagents and instruments.

Fluorescence imaging microscopes and fluorescent reagents have both evolved greatly in the past 10 years. Sensitive imaging cameras developed over the last decade allow detection of fluorescence signals from even a single fluorescent tag on a protein. At the same time, numerous antibody markers for growth control proteins and DNA probes for chromosomal alterations have been discovered and these can be labeled with the new multicolor fluorescent dyes for detection by microscopy. Image analysis software automatically localizes and quantifies of as many as 5-6 of these different color fluorescent markers in the individual cells of a preparation. The results is that powerful methods for multiparameter analysis of molecular structures and dynamic processes are now accessible to the pathologist.

DNA Probes↗
PubMed2006

Multiplex analysis of inflammatory signaling pathways using a high-content imaging system.

This chapter describes a robust high-content cellular screening assay to simultaneously analyze the spatiotemporal activation of three different kinase-associated signaling pathways involving NF-kappaB, JNK, and p38, all of which are closely implicated in proliferative and proinflammatory responses. Signal transduction is dependent on the translocation of NF-kappaB p65 and phosphorylated c-Jun and p38 from the cytosol to the nucleus, and fluorescent immunolabeling was used to monitor changes in their cellular distribution. Cellular screening, data acquisition, and data interpretation were conducted on the ArrayScan HCS Reader (Cellomics Inc., Pittsburgh, PA). Assay adaptation to various cellular systems is feasible when sufficient separation of the nuclear and cytosolic compartment can be achieved and if cell adhesion properties permit proper attachment to the culture plates. Substitution of NF-kappaB p65 and phosphorylated forms of c-Jun and p38 as targets to analyze other translocating components is possible and is limited primarily by antibody specificity and the risk of fluorescent bleed-through between emission channels. Because assay validity is particularly confounded by inadequate spectral separation of the detection dyes in multicolor labeling assays, means of eliminating or counterbalancing staining artifacts are illustrated. Also, protocol parameter settings important for imaging and image processing are described, including object identification, image exposure settings, separation of cytosolic and nuclear regions, number of cells sufficient for analysis, and the use of gating thresholds critical for cell sorting and subpopulation analysis. This assay is a useful tool to investigate the interplay between signaling pathways and the mode of action, potency, and selectivity of compound inhibition of specific target molecules in a cellular context.

Cell Nucleus↗
PubMed1994

Spectra of fluorescent dyes used in flow cytometry.

Flow cytometry uses a relatively small set of dyes for immunochemistry and nucleic acid detection, most of which have been known and used reliably in flow cytometry for several years. These can usually be combined to make simultaneous two-color measurements of multiple cell-surface antigens and nucleic acid content. Because of the overlap of dye spectra and difficulties in finding dyes with substantial Stokes shifts that can be excited by the argon laser, simultaneous three-color or more detection can be more difficult. A basic knowledge of the factors that go into producing the fluorescent signal, including the spectra of dyes and their overlap, is necessary in planning multicolor experiments. By contrast, there have been a number of new fluorescent probes developed for detecting ions, membrane potential, metabolism, organelles, and other properties of living cells as well as for determining cell viability, proliferation, and cell tracking. So far most of these physiological probes are being used only for fundamental research rather than for cell classification. However, as research activity expands in this area, its diagnostic potential is likely to be increasingly appreciated.

Animals↗