question: What makes permanent marker so permanent?
comment: The issue isn't getting it to stick, it's getting it to stay sticking in the presence of water. Water is a pretty good solvent for most things, and permanent markers have a combination of chemicals that don't react that much with water, meaning it stays sticking to whatever it was put on.
passages: In addition to being used for labeling microscopy slides, permanent markers can actually be used to do a negative stain of a bacterial sample. This means the background is stained with the marker, but the bacteria are not. The bacteria can be seen because they are unstained (lighter) while the background is stained (darker).
  
  Section::::Removal.
   The permanent marker was invented in 1952 by Sidney Rosenthal.
  
  Section::::Applications.
  
  Section::::Applications.:General purpose.
  
  They are used for writing on metals, plastics, ceramics, wood, stone, cardboard etc. However, the mark made by them is semi-permanent on some surfaces. Most permanent marker ink can be erased from some plastic surfaces (like polypropylene and teflon) with little rubbing pressure. Fine-tipped permanent markers are used to write on CD / DVD surfaces.
  
  They can be used on normal paper, but the ink tends to bleed through and become visible on the other side. 
  
  Section::::Applications.:Use in microscopy.
   Most brands of "OLFA" marker wipe off easily with acetone free nail polish remover, the kind containing ethyl acetate, a relatively non-toxic organic solvent.
  
  Some markers are designed to be long lasting, for instance by having two inks, one specialized to resist solvents, and one specialized not to fade. These can be available in refillable form.
   Section::::Types.
  
  Section::::Types.:Permanent marker.
  
  Permanent markers are porous pens that can write on surfaces such as glass, plastic, wood, metal, and stone. The marks made by such pens are however, not permanent on some plastics like Teflon, polypropylene etc., and can be erased easily. The ink is generally resistant to rubbing and water, and can last for many years. Depending on the surface and the marker used, however, the marks can often be removed with either vigorous scrubbing or chemicals such as acetone.
  
  Section::::Types.:Highlighters.
   A selectable marker protects the organism from a "selective agent" that would normally kill it or prevent its growth. In a transformation reaction, depending on the transformation efficiency, only one in a several million to billion cells may take up DNA. Rather than checking every single cell, scientists use a selective agent to kill all cells that do not contain the foreign DNA, leaving only the desired ones.
   A permanent marker or indelible marker is a type of marker pen that is used to create permanent or semi-permanent writing on an object. In general, the ink comprises a main carrier solvent, a glyceride, a pyrrolidone, a resin and a colorant, making it water resistant. It is capable of writing on a variety of surfaces from paper to metal to stone. They come in a variety of tip sizes (ultra fine to wide), shapes (chisel point, bullet tip, and wide bristle), and colors (metallic, or ultraviolet reactive). Like spray paint, these markers contain volatile organic compounds which evaporate to dry the ink. Due to compounds such as toluene and xylene often being present in permanent markers, they have a potential for abuse as a recreational drug.
   Section::::Application of newer techniques.:Application of molecular markers.
   Section::::Mapping of genetic markers.
   Molecular genetic markers can be divided into two classes a) biochemical markers which detect variation at the gene product level such as changes in proteins and amino acids and b) molecular markers which detect variation at the DNA level such as nucleotide changes: deletion, duplication, inversion and/or insertion. Markers can exhibit two modes of inheritance, i.e. dominant/recessive or co-dominant. If the genetic pattern of homo-zygotes can be distinguished from that of hetero-zygotes, then a marker is said to be co-dominant. Generally co-dominant markers are more informative than the dominant markers.
  
  Section::::Uses.
   Section::::Selection for major genes linked to markers.
   Over time, the amalgam particles embedded in the soft tissues corrode. Macrophages take up the exogenous particles, and the silver in amalgam leads to staining of collagen fibers.
  
  A similar appearance can be caused by implantation of graphite (e.g. from pencil leads), and is sometimes termed a "graphite tattoo", although this is less common than tattooing with amalgam.
  
  Section::::Diagnosis.
   Genetic markers can aid in the development of new novel traits that can be put into mass production. These novel traits can be identified using molecular markers and maps. Particular traits such as color, may be controlled by just a few genes. Qualitative traits (requires less that 2 genes) such as color, can be identified using MAS (marker assisted selection). Once a desired marker is found, it is able to be followed within different filial generations. An identifiable marker may help follow particular traits of interest when crossing between different genus or species, with the hopes of transferring particular traits to offspring.
   BULLET::::- Insertion of a tympanostomy tube. If aspiration is performed as part of the insertion, the risk of tympanosclerosis occurring increases. Risk also increases if a larger tube is used, or if the procedure is repeated.
  
  BULLET::::- Atherosclerosis
  
  BULLET::::- There is ongoing research as to whether or not cholesteatoma is associated with tympanosclerosis. If there is an association, it is likely that the two conditions co-exist.
  
  Section::::Pathophysiology.
  
  Increased fibroblast activity results in deposition of collagen. Calcium phosphate plaques then form in the lamina propria of the tympanic membrane.
  
  Section::::Diagnosis.
   Section::::Mechanisms of Pb loss.
  
  Section::::Mechanisms of Pb loss.:Solid-state diffusion.
  
  Solid-state diffusion is the net movement of atoms in solid phase, from region of higher concentration to that of lower concentration. It is easy to imagine diffusion in liquid phase as ink spreading in water. Solid-state diffusion of Pb is the net exchange of Pb in the solid mineral with the external environment, which is usually a fluid. In most of the cases, Pb is transported from the mineral to the fluid, resulting in Pb loss and thus age resetting.
   Genetic markers can be used to study the relationship between an inherited disease and its genetic cause (for example, a particular mutation of a gene that results in a defective protein). It is known that pieces of DNA that lie near each other on a chromosome tend to be inherited together. This property enables the use of a marker, which can then be used to determine the precise inheritance pattern of the gene that has not yet been exactly localized.
   There are many types of genetic markers, each with particular limitations and strengths. Within genetic markers there are three different categories: "First Generation Markers", "Second Generation Markers", and "New Generation Markers". These types of markers may also identify dominance and co-dominance within the genome. Identifying dominance and co-dominance with a marker may help identify heterozygotes from homozygotes within the organism. Co-dominant markers are more beneficial because they identify more than one allele thus enabling someone to follow a particular trait through mapping techniques. These markers allow for the amplification of particular sequence within the genome for comparison and analysis.
   Paint markers, and permanent markers generally, contain the toxic compounds xylene or toluene. Like spray paint, these markers give off volatile organic compounds, which can be dangerous when not used in a well ventilated area or with a particulate mask. Gloves can also be worn to avoid absorption through the skin.
  
  Section::::Solidified paint pens.
   There are several different methods of extraction which are currently being used for template removal. These have been grouped into 3 main categories: Solvent extraction, physically assisted extraction, and subcritical or supercritical solvent extraction.
  
  Section::::Template removal.:Solvent extraction.
   One of the hallmarks of arterial claudication is that it occurs intermittently. It disappears after a very brief rest and the patient can start walking again until the pain recurs.
  
  The following signs are general signs of atherosclerosis of the lower extremity arteries:
  
  BULLET::::- cyanosis
  
  BULLET::::- atrophic changes like loss of hair, shiny skin
  
  BULLET::::- decreased temperature
  
  BULLET::::- decreased pulse
  
  BULLET::::- redness when limb is returned to a "dependent" position (part of Buerger's test)
  
  All the "P"s
  
  BULLET::::- Pallor increase
  
  BULLET::::- Pulses decreased
  
  BULLET::::- Perishing cold
  
  BULLET::::- Pain
  
  BULLET::::- Paraesthesia
  
  BULLET::::- Paralysis
  
  Section::::Causes.
   Section::::Genetic markers.
  
  In genetics, a molecular marker (identified as genetic marker) is a fragment of DNA that is associated with a certain location within the genome. Molecular markers are used in molecular biology and biotechnology to identify a particular sequence of DNA in a pool of unknown DNA.
  
  Section::::Genetic markers.:Types of genetic markers.
   The Marker degradation is a three-step synthetic route in steroid chemistry developed by American chemist Russell Earl Marker in 1938–40. It is used for the production of cortisone and mammalian sex hormones (progesterone, estradiol, etc.) from plant steroids, and established Mexico as a world center for steroid production in the years immediately after World War II. The discovery of the Marker degradation allowed the production of substantial quantities of steroid hormones for the first time, and was fundamental in the development of the contraceptive pill and corticosteroid anti-inflammatory drugs. In 1999, the American Chemical Society and the Sociedad Química de México named the route as an International Historic Chemical Landmark.
   BULLET::::- at some point prior to the onset of mitosis, the promoters of genes that exist in a transcription-competent state become "marked" in some way,
  
  BULLET::::- this "mark" persists both during and after mitosis, and
  
  BULLET::::- the marking transmits gene expression memory by preventing the mitotic compaction of DNA at this locus, or by facilitating reassembly of transcription complexes on the promoter, or both.
  
  Section::::Bookmarking as selective maintenance of an open chromatin state.
   Artifacts are structures or features in tissue that interfere with normal histological examination. Artifacts interfere with histology by changing the tissues appearance and hiding structures. Tissue processing artifacts can include pigments formed by fixatives, shrinkage, washing out of cellular components, color changes in different tissues types and alterations of the structures in the tissue. An example is mercury pigment left behind after using Zenker's fixative to fix a section. Formalin fixation can also leave a brown to black pigment under acidic conditions.
  
  Section::::History.
   The gene of interest directly causes production of protein(s) or RNA that produce a desired trait or phenotype, whereas markers (a DNA sequence or the morphological or biochemical markers produced due to that DNA) are genetically linked to the gene of interest. The gene of interest and the marker tend to move together during segregation of gametes due to their proximity on the same chromosome and concomitant reduction in recombination (chromosome crossover events) between the marker and gene of interest. For some traits, the gene of interest has been discovered and the presence of desirable alleles can be directly assayed with a high level of confidence. However, if the gene of interest is not known, markers linked to the gene of interest can still be used to select for individuals with desirable alleles of the gene of interest. When markers are used there may be some inaccurate results due to inaccurate tests for the marker. There also can be false positive results when markers are used, due to recombination between the marker of interest and gene (or QTL). A perfect marker would elicit no false positive results. The term 'perfect marker' is sometimes used when tests are performed to detect a SNP or other DNA polymorphism in the gene of interest, if that SNP or other polymorphism is the direct cause of the trait of interest. The term 'marker' is still appropriate to use when directly assaying the gene of interest, because the test of genotype is an indirect test of the trait or phenotype of interest.
   BULLET::::- During placement of an amalgam filling, e.g. if abrasions on the mucosa are present which allow entry of amalgam dust
  
  BULLET::::- Shortly after placement of an amalgam filling, e.g. amalgam particles can contaminate dental floss and lead to linear amalgam tattoos in between the teeth, especially if flossing is carried out immediately after placement of an amalgam filling with a mesial or distal aspect
  
  BULLET::::- Polishing of an amalgam filling
  