Define the petrifilm (dry film) method, Biology

Assignment Help:

Define the Petrifilm (dry film) Method?

An alternative method to the conventional SPC is a Petrifilm (dry film) method. It is a non-petri dish plating system where a layer of nutrient gel is present on a paper backing covered by a thin flexible film. Indicator dye - tetrazolium- is present which imparts red colour to the colony. All red spots are counted as coloues. Petri films can also be used for detection and enumeration of specific groups such as coliforms.

Another method uses spiral plater, which is a mechanical device that distributes the liquid inoculum on the surface of the rotating agar medium plate. Special counting grid is used for enumeration of colonies. Here less agar is used as compared to standard plating and also more samples per hour can be examined. The method is, however, more suited for liquid foods.


Related Discussions:- Define the petrifilm (dry film) method

Which hormones secreted by the adenohypophysis, Q. What are the hormones se...

Q. What are the hormones secreted by the adenohypophysis? What are their respective functions? The ACTH (adrenocorticotropic hormone), adenohypophisys secretes GH (growth hormo

Bioclimatology effect of climate on distribution of organism, Bioclimatolog...

Bioclimatology: This is the study of effect of climate on distribution of organisms. Bioclimatology is the inter-disciplinary field of science which studies the interactions betwe

Strain of fusarium moniliforme, Q. Strain of Fusarium moniliforme? It w...

Q. Strain of Fusarium moniliforme? It was first obtained from a strain of Fusarium moniliforme isolated from southern leaf blight- damaged corn seed as a water soluble toxin.

A fruit fly has four pairs of chromosomes in its cells, A fruit fly has fou...

A fruit fly has four pairs of chromosomes in its cells. At meiosis, how many dissimilar combinations of maternal and paternal chromosomes are possible in the gametes? In gamet

What are food hydrocolloids, What are food hydrocolloids? Food hydroco...

What are food hydrocolloids? Food hydrocolloids are hydrophilic polymers of vegetable, animal, microbial or synthetic origin that generally contain many hydroxyl groups and ma

Which of following is not true regarding the immune response, Which of the ...

Which of the following is not true regarding the immune response? Answer The immune response uses chemical and phagocytic cells to destroy foreign cells. Once initiated, the immune

Mechanoreceptors - receptors, Mechanoreceptors - Receptors Mechanorece...

Mechanoreceptors - Receptors Mechanoreceptors involve those receptors involved in perception of touch, pressure, tension, hearing, vibration, gravity, muscle tension etc. Th

Briefly explain about phase of the plasmodium life cycle, Q. To which phase...

Q. To which phase of the plasmodium life cycle do the typical chills and fever of malaria correspond? The typical fever and chills episodes of malaria correspond to the phase w

What is the difference between facilitated and diffusion, Q. What is the di...

Q. What is the difference between facilitated and simple diffusion? Facilitated by which kind of molecule does the term "facilitated" mean? Simple diffusion is the direct passa

Define partition chromatography - basic separation technique, Define Partit...

Define Partition chromatography - basic separation technique? It is a technique in which separation is achieved as a consequence of the relative solubility of a substance in th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd