Terms

Apoptosis: Programmed cell-death. The process by which the body regulates the erratic growth of cells by insructing certain cells to die. This makes it possible for normal cell renewal (rejuvenation), and its failure leads to cancer.

Cloning: In this context it means the production of cells by non-sexual means - not just the duplication of animals/plants. It is important to note that clones aren't always identical copies of the original. However the aim of cloning in research is to have genetic uniformity.

Colonies: When cells duplicate they form clusters, known as 'colonies'. Culture Medium: for cells to duplicate they need a food source, and some basal structure on which to grow. The growth medium should be a well-balanced mixture of ingredients and growth factors. Generally it is a form of jelly [jello] isolated from seaweed.

Cytoplasm: what would remain within a cell membrane, if you removed the a) nucleus, which contains the DNA and chromasomes and b) the mitochondrial DNA.

Diploid: The normal state of a cell in which all chromosomes, except the sex-specific chromosomes, are in pairs (one from each parent) which are structurally similar.

Electrophloresis A technique used to examine damage to DNA. It relies on the use of small DC currents attracting the fragments of the DNA at different rates through a resistant gell.

Growth medium:This must provide all the nutrients and essential chemicals the cell needs to duplicate. Oxygen is also needed.

Haploid cells: These only have a single set of unpaired chromosomes (ie sperm and ova)

Meiosis: In Biology this is the type of cell division that results in two daughter cells each with half the chromosome number of the parent cell. This type of cell division happens in the testicles and ovary, in the production of gametes.

Micronucleated cell: A cell which has been damaged at the DNA level, resulting in the mytosis operations being arrested. Typically the nucleus contains only small groups of chromosome fragments.

Multinucleated:When things go wrong in cell division, it is not uncommon to find cells with more than one nucleus. This is usually taken as a good indicator of problems. Such cells are sometimes known as "giant cells".

Mutation: The chromasomes have divided to form new pair of cells, but the fragments of the DNA have rejoined in an incorrect order, resulting in a change in the operations of the cell. Usually mutant cells are targeted for apoptosis (programmed cell death) but not always.

Mytosis: This is the normal type of cell division that results in two daughter cells, each of which will have the same number and kind of chromosomes as the parent nucleus. This is typical of ordinary tissue growth.

Neoplasm: A new and abnormal growth of tissue of the type that is characteristic of cancer.

Senesecence: The process of age deterioration. All cell lines ultimately lose the power of division and growth.

Telemarese: Gene-like structures on the end of chromasomes which determine how many times they can divide. They are a safety mechanism, designed to prevent uncontrolled duplication of cells. Iin the growth of tumours they no longer function as intended.

Zygote: This is a fertilised egg or ovum. It is a diploid cell resulting from the fusion of two haploid gametes (ie a sperm and an egg yolk).

Generally the cells will be placed in a petri-dish on a substrata of a gell-like substance known as the culture medium which has been infused with a growth medium to provide nutrients. The dishes will then be placed overnight or longer in an incubator with controlled temperature.

At some stage the test substance or event (magnetic, electrical, radio etc) will be applied to some of the 'colonies of cells' in the culture, while not to others. Those not receiving the application are the controls and it is essential that they are treated the same as the test cells in every other respect during the test period.

Later the two groups of cultures can be compared.

• It is a quick, easy and relatively cheap form of research to perform once the laboratory has been established.

• Large numbers of possible harmful chemicals (for instance) can be checked at one time, so it is an ideal technique for large-scale testing.

• It enables the testing of isolated factors on specific cells, so it helps the scientist hone-in on actual cause-effect relationships.

• It often provides scientific insights at the most fundamental level ... with the DNA, chromasomes, and the functional and survival [and destructive] mechanisms of cells.

The are many available techniques used in biological research, and test-tube laboratory work, tissue cultures, etc. is only a few. What is more, In Vitro techniques are rarely be used without the support of other research techniques

The obvious disadvantage associate with In Vitro research is that the scientists are not dealing with real-life humans, and therefore the test environment appears to be entirely artificial -- perhaps bordering on the irrelevant. When it produces adverse results it will generally be attacked by science-lobbyists on this ground, and pure laboratory research is often too-easily dismissed by the popular media as irrelevant.

However this is true of almost all research techniques. No technique is ever conclusive in isolation, but by reporting and criticising In Vitro research in isolation it can be ridiculed or trivialised by the ignorant, and ignored by those who only have a superficial understanding of biology.

The same happens with the In Vivo (with Life) forms of live animal research which are often dismissed with the totally simplistic argument that "Mice aren't Men"! The corporate health lobbyists know this form of moronic ridicule often carries considerable weight with ignorant journalists and newspaper readers alike. .

The fact is, of course, that DNA is DNA whether it is in mice or men. And humans and all animals are made up of cells with the same basic DNA, and with chromosomes which divide and proliferate in the same basic way. All of this research is highly relevant; it is just that no one technique provides any total solution.

Neither In Vitro or In Vivo research findings can ever prove causality at a human level. What may be toxic to rats, may not be to mice -- yet these are closely-related species ... so it is fairly obvious that in many studies, research on mice might not necessarily transfer directly to problems of human health. However, since millions of mice are being used every year in laboratories around the world by researchers working for health authorities and pharmaceutical corporations; by independent scientists interested in human, not animal health; and by all sorts of regulatory agencies, it is obvious that the relationship between mice and men are sufficiently close to warrant the utmost attention when an adverse discovery is made.

And it also obvious that this differentiation may be exaggerated at the In Vitro cell level. But a well-designed tissue culture experiment is generally an excellent indicator of how things work at the live-animal level, and that is a good indicator of possible effects at the human level. So this type of laboratory research provides a tool for isolating and analysing possible mechanisms beyond the reach of other techniques.

The In Vitro laboratory needs to have strict procedures to prevent the introduction of fungi, bacteria, viruses or other microorganisms into the cell, tissue and organ cultures under test and also prevent cross contamination of cell cultures from one batch to another. Very strict laboratory standards should apply -- but very often, they don't. See GLP

Miscellaneous information

Cell Division

Humans and other multicelled organisms replace their worn-out cells through cell division -- a process called mytosis -- which leaves the 'daughter' cells capable of further division by the same process. However, this ability to double is not unlimited, and eventually cell division halts. With humans this occurs after 52 divisions (on average -- known as the Hayflick limit) at which stage the cell becomes 'senescent'.

Mytosis ceases because the protective elements of DNA attached to the end of a chromosome (known as telomeres) run out. Cancer cells, however, don't degrade in the same way because the enzyme telomerase, which appears to be common in cancerous cells, acts to rebuild the telomeres thus allowing the cell division to continue indefinitely and in an uncontrolled way. See more

Cell Repair

It is important to realise that damage to DNA and incorrect linking of genes during cell division and the duplication of chromasomes, is sufficiently common that we should regared this as part of the normal process (although clearly it is undesirable, since it can lead to abberations and mutations). Cells have extremely effective cell-repair mechanisms which correct such defects. However this also introduces a further possible mechanism that can lead to EMF damage: it may cause direct chromasome damage or prevent the elements joining in a correct order during mitosis, or it may simply disrupt the normal repair mechanisms.

Assay techniques:
This refers to the various techniques available to the molecular biologist to determine what changes have been made at the cell level, and what damage has been done.

• Comet Assay: This has become a favourite technique in recent years for determining how much damage has been done to the DNA, and it can operate at a single-cell level. It is also known as "Electrophlorescis".

  "Lysing" chemicals are used on the cell/cells to dissolved the outer membranes, and the chromasomal genes/units (which are semi-conductive and therefore electrically active) are dragged through a resistant gell medium by a low-voltage DC current. Different lengths of DNA will have different attractive forces and offer different degrees of resistance. So the cell moves through the gell with a comet-like tail of broken DNA preceeding it (the nucleus offers the most resistance). The fragmented DNA pieces can be seen under ultraviolet light, and estimations can be made of the damage.

• Micronuclei Assay: When chromasome division is disrupted by radiation, chemicals, etc. a higher than normal level of cells will be produced which do not have a full complement of chromasomes because the DNA has been damaged. Therefore the extent of damage can be gauged by counting the cells with micronuclei (or the corresponding macronuclei - or those with two, called binuclei). This type of investigation can use a number of techniques to identify the damaged nuclei, including special dyes that attach to the damaged cells. These techniques are often refered to simply as MN Assays.

Cell Lines and Strains:

• Cell line: A cell line with known characteristics is deliberately propogated from a primary culture as a laboratory tool. Each generation constitutes a subculture. The term 'line' implies that it consist of lineages originally present in the primary culture as a "continuous line". Some cell culture which are apparently capable of an unlimited number of population doublings, are known as "immortal cells". The characterization and history of the culture are often published, and cell lines are often sold and exchanged between laboratories.
• Cell strain: A cell strain is derived either from a known cell line by the careful selection or cloning of cells which have specific properties, with a specific features usually defined. The terms finite or continuous are to be used as prefixes if the status of the culture is known.