Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Explain the Serial Dilution Process - Plate Counts?
Dilution factor is the reciprocal of the dilution used. As number of microorganisms in original sample is not known, the original sample is diluted several times in sterile water blanks to ensure that separate colonies are developed and some colony counts will be in the specified range. The process is called serial dilution. The procedure is shown in Figure. Usually a ten-fold serial dilution is used in the process where 1 ml of the sample is transferred to a 9 ml of the diluent to get 1:10 dilution. 1 ml of this is transferred to another tube of 9 ml of diluent to get 1:100 dilution and so on till the required dilutions are obtained.
Figure: Serial dilution process
It is important that the dilution used should produce a limited number of colonies on plate. When many cells are present, overcrowding of cells may not allow many colonies to develop and may also result in many colonies to fuse. This leads to inaccuracies in count. Similarly, too less colonies are not statistically significant. According to Food and Drug Administration, only those plates having 25-250 colonies should be considered for calculation; but most microbiologists use plates with 30-300 colonies to get the microbial numbers in the sample. Plates getting colonies less than 30 are marked too less to count (TLTC) and getting more than 300 are marked as too numerous to count (TNTC) and are discarded.
Was there molecular oxygen in the earth's primitive atmosphere? How has that molecule become abundant? The presence of the molecular oxygen in the primitive atmosphere was prob
composition formation and circulation of lymph
The life of a eukaryotic cell can be explained as a cell cycle. Mitosis and cell division happens in the M phase that lasts for only about 1 h. This is followed by the G1 phase whe
Marek's disease Marek's disease is a lymphoproliferative disease of chicken, quails, bantams and other free-flying birds. It is caused by the Gallid Herpesvirus 2 of subfamily
State the term - localisation scales The localisation scales are also empirically derived, being based on studies of patients with localised brain lesions. There are frontal,
These mycotoxins are structurally and biologically related to the aflatoxins, and like the latter, they cause hepatocarcinogenic activity in animals. Among the organisms that prod
Enumerate the term - pathognomic sign A comprehensive assessment ideally uses all four approaches. Some forms of specialised assessment rely heavily on pathognomic signs, behav
Discuss in detail about the Mitochondria An important function of the cell is to derive energy from the different oxidisable nutrients, such as, carbohydrates and fats supplied
Proteins - classification, composition and biological functions Proteins, as you may already know, are made up of carbon, hydrogen, nitrogen, oxygen and usually sulphur. Prot
Distinct types of proteins Two distinct types of proteins are known: fibrous and globular proteins. Fibrous proteins are insoluble in water and are physically tough, which
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd