Dna measurement

History of DNA

  • Darwin Published On the Origin of Species, Proposing Continual Evolution of Species

    Darwin Published On the Origin of Species, Proposing Continual Evolution of Species
    The Swiss scientist, Friedrich Miescher isolated DNA for the first time. He wanted too study white blood cells because they are low in pus. He than Isolated a material which was well filled in phosphorus and named it "nuclein". Later on it was found in other cells like sperm.
  • Mitosis Observed

    Mitosis Observed
    Walter Flemming was one of the first cytologists to fully detail the movement of chromosomes during mitosis, as well as cell division. Walter found cell division in salamander embryos at fixed intervals. He also was the first too observe the "staining" too observe chromosomes more clearly.
  • Inheritence of Disease Founded

    Inheritence of Disease Founded
    In 1902 the British physician, Archibald Garrod founded a disease named alkaptonuria. This disease had many symptoms causing dark urine, and dark cartilage and tissue, as well as arthritis. Archibald had verified that alkaptonuria was inherited by Mandeline rules and includes rare recessive mutation.
  • Fruit Flies and Chromosomes

    Thomas Hunt Morgan and Columbia University proved that chromosomes in fruit flies are heridetary. They had further made many different parts to genetics. They showed that fruit flies have Drosophila melanogaster. This showed chromosomes carry genes and described the chromosome recombination.
  • X-ray Diffraction of DNA

    British scientist, William Astbury was the first one too diffraction the pattern of DNA. X-ray Diffraction patterns show DNA structures and atomic precision by showing crystalized molecules. William Astbury extracted DNA cells, dipped a needle into a DNA solution and took out a strand containing molecules lined up parrallel.
  • Jumping Genes

    Barbara McClintock found out that genes can jump around on chromosomes. This showed that the genome is much more dynamic. When Barbara figured out that genes can "jump" she than correlated microscopic arrangments of chromosome placements.
  • Genes being Made of DNA.

    Alfred Hershey and Martha Chase showed that DNA of a virus needs to enter a bacterium to infect it. They experimented this and proved that genes are a strong part of DNA. Electron microscope images showed that a bacterial virul named bacteriophage T4 attaches to a bacterium to infect it.

    Francis Crick and James Watson were the first people too figure out the double helix structure of DNA. DNA is full of nucleotides, and are made of three parts: a phosphate group linked to a deoxyribose sugar,and turned linked to one of four nitrogenous bases adenine (A), cytosine (C), guanine (G), or thymine (T). Nucleotides are linked in series into a chain, with phosphate and sugar groups alternating.
  • Human Chromosomes

    Joe Hin Tjio defined 46 as the exact number of human chromosomes. was interested in the chromosomes of cancer cells and how chromosomal abnormalities might correlate with malignant growth
  • Copying Enzymes

    Copying Enzymes
    Arthur Kornberg and his group seperated DNA polymerase. DNA polymersase is an enzyme used for all kinds of DNA techniques and sequencing. They first seperated DNA polymerase from E. coli bacteria. He did this by adding protein to a tube of salt solution holding DNA molecules and nucleotide building blocks, it was able to make new strands of DNA.
  • Chromosome Abnormalities Identified

    Jerome Lejeune a professer and his team found that Down syndrome,happends because of the trisomy 21. Trisomy is having three instead of 2 copies of chromosome 21. This extra copy affects the brain and body cause Down Syndrome.
  • Metabolic Defects in Newborns

    Robert Guthrie is a doctor at the University of Buffalo Children’s Hospital, he found a way to test thinking newborn babies have phenylketonuria. This is an inability to digest the amino acid. He first tested phenylalanine by blood and seeing whether newborns’ blood types affected the growth of a bacterial strain. If there is more phenylalanine in the body it can poison the nervous system and causes
  • First Restriction Enzymes Described

    M. Meselson’s group at Harvard studied the first restriction nucleases. These are known as enzymes that trandformed molecular biologists’ skill to operate DNA.These are found in bacteria, and use the enzymes to digest attacking DNA. The bacteria add methyl groups to their own DNA to guard them from digestion. Molecular biologists began using these enzymes, as well as DNA polymerase and DNA lipase in the early 1970s to cut,control, and study pieces of DNA in a expected and reproducible way.
  • First Animal Gene Cloned

    Stanford and UCSF researchers combined a segment of DNA that had a gene from the African clawed frog named Xenopus with DNA from the bacteria E. coli and positioned the result of the DNA back into an E. coli cell. The frogs DNA was copied and the gene it contained directed the making of a specific frog protein. This was the first time an animal gene was copied.
  • DNA Sequencing

    Sanger and his team expanded a different procedure for sequencing DNA balanced with Maxam and Gilbert. In Sanger's method, he put a marker that attached to the growing ends of DNA chains. This is used most frequently in labs now. Scientists used radioactivity to mark the ends of DNA chains; now, they use colored dyes.
  • First Disease Gene Mapped

    HD is hereditary as an autonomic leading disease. HD causes the death of exact neurons, leading in your midlife to trait jerky movements, physical stiffness, and dementia, with many symptoms that worsen with time. The specific gene was isolated in 1993. A collaborative group of 58 researchers in 6 research groups secluded a gene called huntingtin located on chromosome 4p16.3.
  • First Human Genetic Map

    The first complete genetic map of human chromosomes was supported on 400 restriction fragment length (RFLPs), they are differences in DNA sequences that can be seen by digesting DNA with restricted enzymes. A genetic map contains landmarks which occur in various forms. Tracking which variants are inherited in different people can be used to locate genes responsible for diseases.
  • Microsatellites, New Genetic Markers

    A microsatellite is a stretch of DNA made up of two- four base-pair long sequence that is recurring. For example the stretch of DNA like: CAGCAGCAGCAGCAGCAGCAG. The number of repeats in a given microsatellite varies with different people; this means microsatellites can be used as genetic landmarks to distinguish people. Microsatellites are mainly useful hereditary markers because they are spread throughout the genome and can be noticed easily using the polymerase chain reaction.
  • ESTs, Fragments of Genes

    This is an expressed-sequence tag (EST) which is a stretch of DNA sequence made by copying a portion of an mRNA molecule. All ESTs replicate sequences from genes. They were first proposed as a helpful way to find genes in the genome in 1991. This is about one tenth of the human genome is thought to be transcribed. Looking at ESTs is a way to home in on the expressed, practical sequences in the genome that the nucleus sends out to the rest of the cell.
  • Second-generation Genetic Map of Human Genome

    A team from France had built a low-resolution, microsatellite genetic map of the entire human genome. The very first genetic map that lengthened the entire human genome with microsatellite markers was a large improvement over earlier genetic maps using RFLPs as markers, since microsatellites are more easily discovered and distinguished. Each generation of genetic map had helped with the geneticists more quickly too locate diseased genes on chromosomes.
  • Physical Map of Human Genome Completed

    THis was a physical map that used a sequence tagged site known as STSs as markers too have bigger segments of DNA. One goal of the HGP was completing a map with a marker every 100,000 base pairs by 1998.
  • Testing the Disease

    Testing the Disease
    In 1990, J.L Guenet and his french group he lead indentified this disese with an experiemtn with mice. There had been dark wood shavings in a mouse trap which caused the mice too have darken urine. The had then found out based on this experiment mice carried this chromosome called chromosome 16.
  • Chromosome 22

    The sequence of chromosome 22 gave scientists their first view of the organization of an entire chromosome. The sequencing effort concerned on the long arm of the chromosome. Each chromosome consists of two arms, a shor and long arm. In chromosome 22, the q arm is very rich in genes. The sequence from the long arm is 33,400,000 base pairs in length, and contains at least 545 genes.
  • Full-Scale Human Genome Sequencing

    HGP members advanced their goal of get hold of draft sequence covering 90 percent of the human genome to 2000, a year and a half before projected previously. Full-scale human genome sequencing began.
  • Chromosome 21

    HGP scientists were led by German and Japanese teams to finish the genome sequence of human chromosome 21, the second human chromosome to be fully sequenced. An extra copy of chromosome 21 causes Down syndrome and genes on the chromosome have been linked to diseases like Alzheimer’s and certain forms of cancer.
  • FDA Approves Genetics based Drug to Treat Leukemia

    The FDA accepted an oral medication called Gleevec to treat patients with chronic myeloid leukemia. This happeneds when a certain enzyme that controls cellular growth is abnormally active.Gleevec blocks the activity of the enzyme, slowing the abnormal growth of the white blood cells.