Archive for the ‘DNA’ Category

Chemical molecules are attached to the probe and that will enable the detection of this after a process of hybridization. There are many types of reporter molecules: radioactive (32P, 35S), affinity (Biotin, Digoxigenin …), enzymatic (phosphatase, peroxidase …) and chemiluminescent (esters of acridine).

What factors affect the sensitivity and specificity of the hybridization reaction? Read the rest of this entry »

The introduction of rapid methods of sequencing in the late ’70s represented a major shift in studies of two methods of DNA sequencing of nucleic acids. One of them (Maxam and Gilbert) chemical reagents used to cut DNA at specific base. The other is called enzymatic chain termination or dideoxy (Sanger, Nicklen and Coulson). The purpose of both is to get the whole sequence of each of the bases that form a nucleic acid fragment. Read the rest of this entry »

Hybridization solution: The probe and target nucleic acid are in a liquid. The hybridization conditions must be in order. The rate of formation of the duplex under these conditions is high. The problem with this type of hybridization is the elimination of unreacted probe, using among other methods nuclease S1-precipitation with trichloroacetic or hybridization protection assay. Read the rest of this entry »

Few areas of molecular biology have not changed with the emergence of a number of techniques subsumed under the generic term for Genetic Engineering and interchangeably referred to as cloning, recombinant DNA or genetic manipulation. Before the development of Genetic Engineering was not possible to isolate a particular eukaryotic gene in sufficient quantities for study molecular or your product. Read the rest of this entry »

We can consider the DNA or deoxyribonucleic acid, such as the brain) ~ cell that regulates the number and nature of each type of structure and cellular composition,ansmitting hereditary information and determining the structure of proteins by enzymes that determine the remainder of cellular functions.

At the end of last century was also discovered the existence of a second class of nucleic acid called ribonucleic acid (RNA). The RNA is found both in the core (specifically in the nucleolus) and in the cytoplasm of cells abundantly.

Both types of nucleic acid, DNA and RNA, are simultaneously in eukaryotes (cells with distinct nucleus) and prokaryotes (bacteria, etc.). And only one in the
virus. Read the rest of this entry »

The human genome consists of three billion pairs of nucleotides. Each nucleotide contains one of four nitrogenous bases - A, C, G or T, form the alphabet by which genetic information is stored in the DNA molecule. The grounds of one chain of DNA bases mate with another chain of strictly defined rules (A is paired with T, G - s), it suffices to determine the sequence of bases in one of them.

To identify the specific grounds in some regions of the genome is required sensor capable subnanometrovoe notice the difference between A, T, G and C. The only physical method that has such a high resolution - scanning tunneling spectroscopy. However, the sequencing of the length of the billions of links are most often used, not the physical and chemical sposoby.Genom man was decoded using the technique developed in the late 1970’s. American biochemist Frederick Sanger. This procedure is preceded by cutting sequencing study of the DNA molecule into fragments, cloning them in E. coli and multiple duplication to obtain millions of copies of each fragment. As a result of the last round of duplication, conducted in special circumstances, receive a set of copies of fragments of various lengths, each of which ends with a fluorescently labeled nucleotide. Fragments are separated by length using electrophoresis, register the light signal from each of them as it passes through the detector and obtain the nucleotide sequence of the original circuit.
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Not many people get organic substances in pure form (or in the form of homogeneous mixtures) are already in antiquity. Fats and oils, no doubt, are among their number. Therefore, their names are in all languages simple native, although the chemists call them also lipids (from the Greek “liposome” - fat). To detect them was easy because they occur in all living organisms, and often in large numbers. Nature took care of animals and plants, providing them with supplies of fuel for cold and hungry days. Animals put this fuel, mainly around the internal organs and under the skin to fat deposits at the same time served as a shock-absorbing cushion shocks and heat insulator. Other animals also have not forgotten either himself or his offspring. Those who lay their eggs, or caviar, to supply embryos and larvae necessarily include a variety of lipids in the yolk. Plants that produce seeds, also supply the germ oils. Lipids are not only fuel but also the raw material for production of active molecules, and building material for body cells, and storage of vitamins - in general, it is difficult to do without them.
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Heredity, genes, DNA … It seems that these words have long ceased to be scientific terms, entered into everyday life and is now familiar to every senior, not to mention the students. But there was no DNA, most of us have never seen, though to see it - it is quite real, even in the home. In one of the genetic laboratory on the wall, for example, that the instruction:

• Find something that contains a lot of DNA. For example, green peas (but may be chicken liver, herring roe, or onion).
• Put in a blender about 100 ml (half a cup) of this product, add 1 / 8 teaspoon of salt and 200 ml (cup) of cold water. Whips within 15 seconds. Mixer «cook» you pea-cell soup.
• Strain the mixture through a strainer or a piece of nylon (stockings quite fit). In the obtained pulp, add 1 / 6 of its number (it will be about 2 tablespoons) of liquid detergent (for dishes, for example) and stir well. Leave on for 5-10 minutes.
• Pour the liquid in test tube or other glass vessel, so that each was filled with no more than a third volume.
• Add to each tube for a bit, or the juice squeezed out of a pineapple, a contact lens solution and gently shake it, turning and bending the tube (if you shake too vigorously, break up DNA and did not see it).
• Tilt the tube and slowly pour into it a little bit of ethyl alcohol, that it formed a layer on top of pea mixture. Leite, while a mixture of alcohol and not be a tie. DNA pops up in the form of flakes.
• Wooden stick (pencil) to catch them and examine under a microscope.

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