Available online
Description
This programme is one of a series of six which concentrate on crucial biochemical techniques, their practice and applications, presented in a studio based laboratory setting. The programme is devot...ed entirely to microbiology. After a brief introduction by Dr. Cohen, Dr. Noel Carr demonstrates how widespread micro organisms are by demonstrating the colonisation of bread and fruit by bacteria and moulds, and then the growth of micro-organisms on plates of sterile agar, from samples of tap water, breath, hair and soil, and on sterile agar after exposure to the air. Bacteria from one of the plates are briefly examined under a microscope. Dr. Carr then demonstrates the essentials of sterile technique, including the preparation of sterile growth vessels and growth medium. He then demonstrates the sterile transfer that results eventually in the isolation of a pure culture, and then the means of keeping isolated strains in continuous scored culture. He demonstrates solid to liquid culture transfer and liquid to liquid and finally the harvesting of micro organisms from large liquid cultures.
This programme is one of a series of six which concentrate on crucial biochemical techniques, their practice and applications, presented in a studio based laboratory setting. The programme is devot...ed entirely to microbiology. After a brief introduction by Dr. Cohen, Dr. Noel Carr demonstrates how widespread micro organisms are by demonstrating the colonisation of bread and fruit by bacteria and moulds, and then the growth of micro-organisms on plates of sterile agar, from samples of tap water, breath, hair and soil, and on sterile agar after exposure to the air. Bacteria from one of the plates are briefly examined under a microscope. Dr. Carr then demonstrates the essentials of sterile technique, including the preparation of sterile growth vessels and growth medium. He then demonstrates the sterile transfer that results eventually in the isolation of a pure culture, and then the means of keeping isolated strains in continuous scored culture. He demonstrates solid to liquid culture transfer and liquid to liquid and finally the harvesting of micro organisms from large liquid cultures.
| Item code: | S2-1; 05 |
|---|---|
| First transmission date: | 19-08-1972 |
| Published: | 1972 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:22:59 |
| + Show more... | |
| Producer: | Roger Jones |
| Contributors: | Noel Carr; Norman Cohen |
| Publisher: | BBC Open University |
| Keyword(s): | Bacteria; Biochemical techniques; Bread and fruit, tap water, soil; Isolated strains; Microbiology; Micro-organism collonisation; Practice and applications; Solid to liquid culture transfer; Sterile techniques |
| Footage description: | N.R.Cohen with a copy of the "Biochemical Journal". He points out that about 50% of papers on the subject are concerned with the biochemistry of microorganisms. He discusses why this should be so. Noel Carr with some samples of damp bread which has been lying around for some days. Moulds and bacterial growths have formed all over the bread. Carr uses this simple experiment to point out that microorganisms are all around. Carr demonstrates how micro-organisms can be grown for laboratory study. He places several drops of nutrient into a sterile petri dish. Carr shows a petri-dish which was prepared as the one above, then exposed to the atmosphere, and then incubated for several hours. A great variety of micro organic growth is seen on the dish. He then shows a petri dish which was exposed to a puff of breath and incubated. Again there is massive microbial growth but less variety. Carr next shows a petridish with a hair added, then incubated. Massive microbial growth Is seen around the area of the hair. Carr next shows a petridish which had pieces of ordinary soil added then incubated. Again massive microbial growth can be seen. Finally a petri dish which has been exposed to a few drops of tap water. Again microbial growth is seen in the dish. Carr removes a small sample of bacteria from one of the dishes and places it on a slide under a microscope. Shot of the bacteria under the microscope. Carr beains his demonstration on methods for isolating micro-organisms for laboratory study. He explains, first, the advantage of sterile, plastic, disposable petri dishes over the conventional glass type. Carr explains how a nutrient jelly for growing the micro-organism in a petri dish is prepared. He demonstrates and explains the "streak out" technique for isolating micro-organisms of one species. He shows the result but explains that the process must be repeated several times to ensure that single cell colonies have been obtained. Carr explains how a microbial culture, once obtained and purified, is kept. He demonstrates by transferring a sample from a petri dish to a slope of agar in a test tube. This is incubated at 30° C. Carr shows a sample of microbes growing in a liquid nutrient. He explains and demonstrates how microbes can be transferred from one liquid nutrient to another without contamination Carr with a large flask containing a culture in a liquid nutrient. He explains how the organisms are separated from the nutrient by centrifugation. Carr shows a sample which has been centrifuged. |
| Master spool number: | 6LT/70363 |
| Production number: | 00521_2130 |
| Videofinder number: | 2819 |
| Available to public: | no |
