Blood pressure measurement

Blood pressure measurement. Doctor holding the pump of a sphygmomanometer as he measures a patient's blood pressure. Blood pressure is an important measure of health. High blood pressure (hypertension) puts a great deal of strain on the heart, and is one of the major risk factors in heart attacks and strokes.

Bacteriophage viruses

Bacteriophage viruses. Computer artwork of T- bacteriophages, or phages (small particles in image), infecting E. coli bacterium cells (larger, cylindrical particles in image). Phages are viruses that infect bacteria. T-phages consist of an icosahedral (20- sided) head, which contains the genetic material (either DNA or RNA), and a thick tail with several bent tail fibres. The tail is used to inject the genetic material into the host cell to infect it. The phage then uses the bacterium's genetic machinery to replicate itself. When a sufficient number have been produced the phages exit the cell by lysis, a process that kills the cell.

Insulin receptor, molecular model

Insulin receptor. Molecular model of the insulin receptor molecule (brown, orange, blue, grey and mauve) bound to an insulin molecule (red and yellow). Both the surface structure (blobs) and secondary structure (ribbons) of the receptor are shown. The insulin receptor is a transmembrane protein, that is it spans the cellular membrane (yellow and cream). Binding of insulin to the extracellular part of the protein activates a number of changes inside the cell that lead to the uptake of glucose, the synthesis of glycogen and fatty acids and glycolysis, the production of energy from glucose.

Antibiotic resistance enzyme molecule

Antibiotic resistance enzyme. Molecular model of the metallo-beta-lactamase protein fold, a part of metallo-beta-lactamase enzymes, in a bacterial cell. This bacterial enzyme confers antibiotic resistance on cells that carry it. The gene that codes for the enzyme is found on a plasmid, a ring of DNA that is separate to the cell's main DNA, and so can be transferred between cells in close contact. This is possible even if the bacteria do not belong to the same genus. The enzyme inactivates antibiotics in the beta-lactam group, including penicillin and carbapenems, which are the last line of defence used against other drug-resistant bacteria.

DNA CHIP

DNA chip. Here, the slide after hybridation. The fluorescence reveals the gene expression.

Arabidopsis seedlings, genetics research

Arabidopsis seedlings (Arabidopsis thaliana) being grown in a laboratory. This plant is used as a model organism in plant studies, including plant genetics. It has a relatively small genome for a plant, with only 5 chromosomes. It also grows and reproduces rapidly, taking only 6 weeks to pass through its entire life cycle. Another advantage is that it is relatively easy to manipulate its genome, for example by using bacteria to transfer new DNA to the plant's cells. Photographed at the Plant Development and Genome Laboratory at the University of Perpignan, France.

BIOTECHNOLOGY, GMO

BIOTECHNOLOGY, GMO Illustration of the different techniques for creating GMOs from transformed DNA. On the left, the DNA is introduced into the nucleus of a cell which will grow into a genetically-modified animal. In the center, plant DNA is placed in a plasmid vector and then either transferred to a plant cell indirectly via bacteria or transferred directly to the plant cell through electroporation. On the right, the gene is anchored to metallic particles and transferred directly to the cell using a gene gun. The resulting plant cells then grow into plants.

GM bacterial cultures

GM bacterial cultures on a light box. The bacteria have been genetically engineered to contain a plasmid, a circle of DNA (deoxyribonucleic acid). The plasmid contains a gene (iaaM) that prevents tomatoes from developing seeds. The bacteria are used to multiply the gene many times because of their quick replication rate. The genes will then be inserted into tomato plant genomes. Photographed at the University of Verona, Italy.

Transgenic tomato genome sequencing

Transgenic tomato genome sequencing. Researcher holding a seedless transgenic tomato above a DNA (deoxyribonucleic acid) autoradiogram of its genome. The bands on the film show the position of the four nucleotide bases from DNA. The sequence of bases make up genes, which encode an organism's genetic information. A gene has been inserted into the tomato plant to prevent the development of seeds. Photographed at the University of Verona, Italy.

Transgenic tomato genome sequencing

Transgenic tomato genome sequencing. Researcher watching an electrophoresis gel running to sequence the genome of a tomato that has been genetically modified to be seedless. The bands on the gel show the position of the four nucleotide bases from DNA (deoxyribonucleic acid). The sequence of bases make up genes, which encode an organism's genetic information. A gene has been inserted into the tomato plant to prevent the development of seeds. Photographed at the University of Verona, Italy.