Explain the direct microscopic counts (dmc), Biology

Assignment Help:

Explain the Direct Microscopic Counts (DMC)

The process includes making a smear of food sample on a microscope slide followed by staining with an appropriate dye and viewing and counting under the microscope.  It is widely used for assessing the microbial quality of the milk and dairy products (Breed Count).

The method involves spreading 0.01 ml of the milk sample on 1 cm area of a slide.  After drying and staining the slide, average number of bacteria per microscopic field is counted. The diameter and area of the microscopic field is calculated by micrometry.  Number of bacteria per ml of the milk sample is calculated as:

Number of bacteria/ml = average number of bacteria per microscopic field x number of field x dilution factor.

Number of Microscopic fields = area over which milk is spread ÷ area of one microscopic field  = 100 mm2  ÷ 0.02 mm2 = 5000 field

Dilution factor = 100 (0.01 ml of the sample is plated)

It is rapid and simple method by which cell morphology can be detected. Efficiency can be increased by using fluorescent dye. The method, however, gives the count of both viable and nonviable cells. Sometimes food particles may not be distinguishable from microorganisms. Some microorganisms may not take stain and not be counted. In spite of these drawbacks, it is used for quick assessment of microbial quality of foods. The discussion above focused on the methods we can use to assess the microbiological quality of food samples.


Related Discussions:- Explain the direct microscopic counts (dmc)

Procedure for spore staining in a given bacterial culture, Explain Procedur...

Explain Procedure for Spore Staining in a Given Bacterial Culture Carry out the exercise following the steps enumerated herewith 1. Take a clean, non-greasy slide. Prepare b

Limb regeneration in amphibians, Limb Regeneration in Amphibians In v...

Limb Regeneration in Amphibians In vertebrates, the amphibians particularly the urodeles comprise spectacular power of regeneration. This power of regeneration has made them

Explain metameric in detail., Explain Metameric in detail. A body plan ...

Explain Metameric in detail. A body plan which consists of a series of identical units, metameres, repeated down longitudinal axis of the animal. Every metamere contains identi

Eastern/western/venezuelan equine encephalitis, Eastern/Western/Venezuelan ...

Eastern/Western/Venezuelan equine encephalitis This encephalitis causing group of viral diseases of wild birds including pheasants, chickens, turkeys, ducks and pigeons with a

Explain future challenges of connecting models and data, Explain Future cha...

Explain Future challenges of connecting models and data? Since biological systems are complex, models of biological systems are also complex, and matching models and data is a

What are the two groups of defense mechanisms of the body, What are the two...

What are the two groups of defense mechanisms of the body against foreign or harmful agents? What is the difference between them? The body has many defense mechanisms against f

Write the meaning of polyuria, Q. Write the meaning of Polyuria? Increa...

Q. Write the meaning of Polyuria? Increased Urine (Polyuria): When sugar is increased in the blood it is filtered from the body along with the water. This is the reason for fre

Reproductive organs, Reproductive Organs In several metazoans, gonads ...

Reproductive Organs In several metazoans, gonads are well-defined. Testes and ovaries take up dissimilar shapes and anatomical dispositions. In cases of certain hermaphrodites

Define briefly the enzymatic proteins, Define Briefly the Enzymatic Protein...

Define Briefly the Enzymatic Proteins? The most varied and very highly specialized proteins are those along with catalytic activity - the enzymes. Virtually all the chemical re

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