During real time PCR run using a SYBR green active reference dye, I know that the flourescence from the SYBR green is emmited when the dye is intercalated with the double stranded DNA. What I wnat to know is how the flourescence from the passive reference is emmited.
214111
I have recently wondered the answer to this question myself.  I think that passive dyes, such as ROX, constantly emit a flourescent signal.  This signal is not supposed to be influenced by the PCR reaction cycle (ie "passive").  I believe the ROX dye is a rhodamine labeled amino acid, or maybe a short peptide. Other passive dyes are probably similar.
381612
Due to conjugation given by NO2 group, molecule absorbe blue i.e. visible light & emits its complementary colour ( u might be knowing colour theory ) i.e. yellow.
63078
Preenrichment- for non fat dry milk and dry whole milk, weigh 100g of product and transfer to 1L distilled water containing 2ml of 1%aqueous brilliant green dye.Incubate at 35C for 24 +/- 2hrs. Enrichment- transfer 1ml of pre enrichd smple to 10 ml selenite cystine broth and tetrathionate broth respectively incubate at 35C for 24 +/- 2hrs.streak from enrichment media to the ff diff media: brilliant green, salmonella-shigella and bismusth sulfite incubate at 35C fo 24 +/- 2hrs.\nappearance of typical colonies:\nBGA- colorless, pink to fuchsia, translucent to opaque with surrounding medium pink to red.\nSSA- uncolored to pale pink, opaque, transparent or translucent; some produce black centered colonies.\nBSA- brown black sometimes with metallic sheen.\nsubject for further identification using  TSI agar for confirmation.streak the slant and stabb the butt. salmonella positive TSI cultures have alkaline red slants and acid (yellow) butt with or without H2S (blackening of agar) =)
497168
You mean the wavelength they absorb light? Only aa's with an aromatic ring have any color reactions.  They absob light at about 260 to 280 nanometers.
154332
Paper chromatography is a modern method used separate mixtures. Paper chromatography uses paper as the stationary phase and a liquid solvent as the mobile phase.\n\nYou will use paper chromatography to test food colorings to see if the color results from a single dye or mixture of dyes. If you cannot get food coloring you can use colored felt pens or other water soluble coloring pens. Your exercise is simple but uses very essential principles. An optional part of the activity is to check a household product for the presence of the same dyes that are in food coloring.\n\nThe technique relies on the idea that the solvent and the paper both have an attraction for the components in a mixture. The solvent creeps along the surface of the paper. If a material is placed on one spot on the paper and is soluble in the liquid solvent, the material will be dissolved when the solvent moves over it. The material will move along with the solvent. Each compound in a mixture will have its own characteristic balance of attractions to solvent and to paper, so all will not move at the same speed. Eventually this difference in speed will separate the compounds.\n\nIn paper chromatography when the conditions are kept constant, a particular compound always travels a fixed percentage of the distance traveled by the solvent front. The ratio of the distance the compound travels to the distance the solvent travels is called the Rf value. The symbol Rf stands for "retardation factor" or "ratio-to-front". It is expressed as a decimal fraction. When the conditions are duplicated, the same average relative positions will turn up for the solvent and solute; thus the Rf value is a constant for a given compound. The Rf value is a physical property for that compound. The Rf value is useful in identifying compounds, but other properties should be used in combination with the Rf value to confirm compound identification. Since it is difficult for different laboratories to exactly duplicate conditions for a chromatography experiment, Rf values are more useful for comparisons within one lab than for comparisons of data from different labs.\n\nSubstances that are not colored can also be separated by chromatography. They are detected using ultraviolet or black light. These substances appear to glow in the dark.
247266
log on to\n\nhttp://technology.infomine.com/biometmine/biopapers/biomet_advance.pdf\n\n:)
55550
Not sure what you mean: a transparent substance that, when cut/sliced/whatever, will display coloration?\n\nDue to a chemical reaction with the atmosphere? Try a gelatinous material with a fugitive acid and phenolphtalein. As the acid evaporates, the pH will rise beyond the equilibrium of phenolphtalein. (Or some other indicator changing from colorless to colored, closer to neutral.)\n\n\nSometimes coloration can result from surface structure rather than dyes: the brilliant blue butterfly wings of some South-American species result from nano-structures eliminating all non-blue light. Assuming that your substance  is connected by a liquid of similar refractory index, the surface effect will only occur once the surface is hurt and the liquid is allowed to dry away.
281776
They are different varieties due to different in DNA color sequence.This is regulated by gene regulation and expression by making novel proteins.
462220
simple, its all in osmosis. since outside the egg there is a high concentration of solute ( in this case the dye) , some of it goes inside so that the conentrations level out and reach equilibrium. That happens automatically, it goes with its concentration gradient: from high to low concentration. Same happens with water. if you put dye in a cup of water, the concentration of dye spreads along so that there is almost the same amount of dye in each place. the dye goes inside the egg cells thourgh the cell's membrane.
463172
Gene Allele Description\nB=black, b=brown\nC=color deposition, c= no color deposition\n\nParents cross: BbCc  x  BbCc\nGametes: BC; Bc; bC; bc  x  BC; Bc; bC; bc\n\nF1 Punnnet Square\n\n.........BC....Bc....bC....bc\nBC\n\nBc\n\nbC\n\nbc\n\nthe result of the punnet square is as follow:\n\n9/16 B_C_  Black (color deposition)\n3/16 bbCC  Brown (color deposition)\n3/16 BBcc  Yellow (no color deposition)\n1/16 bbcc   Yellow (no color deposition)\n\nratio: 9:3:4\n\ngene c is epistatic on gene B/b
36974
I use a 1 KB DNA ladder for electrophoresis and it comes with a paper to actually tell you which band represents which size fragment. Maybe you could look on the tech company's website. If you do not need to know the actual fragment size of each band, maybe you could just compare to make sure the band you need is there in the first place.
499435
My best guess would be that the chloroplast would be marked as \n"non-self" in the cell and would be degraded in the lysosome. It would be might complicated to keep the chloroplast from being degraded.
431002
The phospate group in DNA would impart a localized negative charge.  There are also amine groups that would support this polar charge.
56304
http://universe-review.ca/I11-21-rRNA1.jpg\nhttp://dna01.bse.kyutech.ac.jp/jouhou/image/dna-protein/all/small_N1qa6.gif\nhttp://dna01.bse.kyutech.ac.jp/jouhou/image/dna-protein/all/small_N1i6u.png
329139
Wow, this answer is gonna be a long one...   There are numerous studies of the charting of the positions of genes on a DNA molecule or chromosome and the distance between genes of Escherisia Coli. It basically comes down to good old conjugation and transduction.  Having sequenced the E. coli K-12 genome, scienctists are creating a knockout of every gene, a clone of every ORF, and an extensive gene expression data set under a variety of physiological conditions. These clones and data sets are made available freely to the community.  Scienctists have also sequenced six additional enterobacterial strains which are pathogens closely related to E. coli K-12, and many plasmids. The comparative genomics aim of this effort is to characterize the gene pool of horizontally transferred elements and virulence determinants known as the pathosphere.\n\nI put a reference on it so be sure to check it out yourself. \n\nA mutator gene, mutD5, whose phenotype is conditional, has been identified in Escherichia coli. By P1 transduction it has been shown to lie at about 5.7 min on the chromosome, being co-transduced with proA and argF. In rich medium, streptomycin- and nalidixic acid-resistant mutation frequencies are 50 to 100 times higher than those in minimal medium. In minimal medium, the mutD5-induced mutation frequencies are still 50 to 100 times above co-isogenic wild-type (mut+) levels. Similar results were obtained with all markers tested. Mutant frequencies can be raised by thymidine in the medium at concentrations as low as 0.04 μM, or by the endogenous generation of thymidine from thymine plus a deoxyribosyl donor. Deoxyadenosine, various ribonucleosides, thymine, and 2-deoxyribose do not stimulate mutation. None of these effects are related to growth rate, since growth rate and mutation rate can be decoupled completely.\n\nThe gntP gene, located between the fim and uxu loci in Escherichia coli K-12, has been cloned and characterized. Nucleotide sequencing of a region encompassing the gntP gene revealed an open reading frame of 447 codons with significant homology to the Bacillus subtilis gluconate permease. Northern (RNA) blotting indicated that the gntP gene was monocistronic and was transcribed as an mRNA with an apparent molecular size of 1.54 kb. The transcriptional start point was determined by primer extension analysis. The gntP gene was found to be under catabolite repression and was not induced by gluconate. Also, expression seemed to be stringently controlled. Several observations indicated that the GntP protein is an inner membrane protein; it contains characteristic membrane-spanning regions and was isolated predominantly from the inner-membrane fraction of fractionated host cells. A topology analysis predicted a protein with 14 membrane-spanning segments. The inability of a mutant strain to grow on gluconate minimal medium could be relieved by introduction of a plasmid encoding the gntP gene. Finally, the kinetics of GntP-mediated gluconate uptake were investigated, indicating an apparent Km for gluconate of 25 microM.
293409
Here it is! With no hustle!\n\n\nFor pure DNA sample at 260nm wavelength measurements,\n\nOD of 1 = 50 micrograms/mL\n\nFor pure RNA, at the same wavelength\n\nOD of 1 = 40 micrograms/mL\n\nPeace!
202452
Rf values should be the same for the same plant pigments whenever you do the chromatogram. What will change is the pigments present and their amounts.