Dayyal Dg.

Dayyal Dg.

Clinical laboratory professional specialized to external quality assessment (proficiency testing) schemes for Laboratory medicine and clinical pathology. Author/Writer/Blogger

For the estimation of hemoglobin by oxyhemoglobin method, blood sample is mixed with a weak ammonia solution and then absorbance of this solution is deliberated in a photometer using a yellow-green filter or measured in a spectrophotometer at 540 nanometer. Absorbance of the test sample is corresponded with that of the standard solution.For the estimation of hemoglobin by oxyhemoglobin method, blood sample is mixed with a weak ammonia solution and then absorbance of this solution is deliberated in a photometer using a yellow-green filter or measured in a spectrophotometer at 540 nanometer. Absorbance of the test sample is corresponded with that of the standard solution.

This method is much similar to cyanmethemoglobin (hemoglobin-cyanide) method.

This method is very simple and rapid but this method is not much reliable as compared to cyanmethemoglobin method because there is no stable standard solution is available, derivatives of hemoglobin except oxyhemoglobin are not measured, and color of oxyhemoglobin solution swiftly dims.

Friday, 23 June 2017 19:25


  • Abdul Qadir Khan Research Laboratories
  • Energy Conservation Cell (ENERCON), Islamabad
  • Drainage Research Institute of Pakistan (DRIP), Hyderabad
  • Forestry Institute, Peshawar
  • Ghulam Ishaq Khan Institute of Advanced Science and Technology, Tarbella
  • Geological Survey of Pakistan, Rawalpindi
  • Irrigation, Drainage, and Flood Control Research Council, Islamabad
  • National Center for Technology Transfer (NCTT), Islamabad
  • National Institute of Health (NIH), Islamabad
  • Nuclear Institute of Agricultural Biology (NIAB), Faisalabad
  • Pakistan Agricultural Research Council (PARC), Islamabad
  • Pakistan Arts Council
  • Pakistan Atomic Energy Commission (PAEC), Islamabad
  • Pakistan Council of Industrial and Scientific Research (PCSIR)
  • Pakistan Science Foundation (PSF), Islamabad
  • Pakistan Health Research Council (PHRC), Islamabad
  • Silicon Institute of Technology, Islamabad
  • Space and Upper Atmosphere Research Council (SUPPARCO), Karachi
Tuesday, 13 June 2017 17:07


Rearing a variety of birds such as chicks, turkeys and ducks is referred to as poultry. Chicken forms the major poultry farming all over the world.
In Pakistan the poultry sector is playing an important role in bridging the gap between the supply and demand for protein. Commercial poultry farming started in Pakistan in the early 1960s and showed rapid growth over the decades. The early growth of this sector was the result of the promotional policies from the Government and the persistency of the poultry farming community. The Government considered the poultry production chain to be a crucial part of the food processing industry and gave special incentives to this sector, and hence the poultry sector was declared free of sales and income tax as well as exempt from import duties for a number of years. As a result, during the early 1970s, the sector saw 20–30% growth per annum, and continued to grow at a rate of 10–15% in the 1980s. The most important reason for this growth was a vibrant domestic market, due to which poultry meat consumption increased more than 4% per year.
In Pakistan, poultry production is one of the most dynamic and well organised sectors contributing 26.8%, 5.76% and 1.26% respectively to total meat production, agricultural sector and overall GDP. In the last few years, the poultry sector has shown excellent growth and has emerged as a source of employment for more than 1.5 million people (GOP, 2014).
The extraordinary progress of poultry farming in Pakistan is due to the following reasons.
  1. Poultry requires less investment.
  2. It generates income in a short span of time.
  3. It provides work round the year.
  4. It can be started as a cottage industry.
  5. It produces good quality of animal proteins. (Nutrient value of egg is 13.3% of proteins; 13.3% of fats; 173 K. cal. of energy; 60 mg. of calcium; 220 mg. of phosphorus and some vitamins, iron efë. About 100 gms. of flesh of chicken consists of 26.0% proteins; 0.6% fats; 109 K. cal. of energy; 25mg. calcium and 245 mg. phosphorus).
  6. It can be started as a self employment scheme.
  7. The feed can be better utilised by poultry. As a result, less food consumption and better growth of poultry are realised.
  8. Poultry is also suitable for mixed farm conditions.
  9. Marketing facilities for the sale of poultry products are available.
The domestic fowl is allowed to move freely in open places in villages. These birds freely move and lay a few number of eggs. This is the only system normally practiced for growing chicks in villages for a longtime. However, this method is not proved to be economical. As an alternative to this, poultry farming is initiated.
Some important aspects are to be followed in poultry farming. They are (1) poultry housing and equipment (2) management of chicks - broilers and layers (3) poultry diseases (4) poultry products, marketing and economics. In poultry farming, the birds may be grown either by the semi intensive system or intensive system.
This system is adopted where the free space available is limited. A space of 20-30 square yards is to be allowed per each bird of outside run. Some times the birds may be allowed to move onto fresh ground.
In this method, proper care is to be taken to grow the chicken.
The intensive system is the common system employed in poultry farms. In this system, birds are grown freely in houses or cages arranged in tiers. Housing is meant for providing ideal conditions for the chicken so as to give efficient production.
Aquaculture, also known as aquafarming, is the farming of fish, crustaceans, molluscs, aquatic plants, algae, and other aquatic organisms. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the harvesting of wild fish. Mariculture refers to aquaculture practiced in marine environments and in underwater habitats.
Aquaculture is a rather recent activity in Pakistan and is still in its infancy; nevertheless there is immense potential for development of the sector. Despite its vast fresh, brackish and marine water resources only carp culture is practiced in inland waters and only on a limited scale, carp are cultured in earthen ponds, using mostly extensive farming practices with very little inputs. In Pakistan, the fish fauna is rich but only seven warm water species and two cold water species are cultivated on a commercial scale. Trials experimenting with shrimp culture have been carried out in the Indus delta region but it did not succeed due to the non-availability of hatchery-produced seed.
The fisheries sector as a whole contributes to about 1 percent to the country's GDP and provides jobs for about 1percent of the country's labour force. Freshwater carp farming is the major aquaculture activity in three of the country's four provinces (Punjab, Sindh and North West Frontier Province [NWFP]). The northern mountains of Pakistan have good potential for trout culture but production in these colder regions is still very small.
Aquaculture in Pakistan is basically a provincial responsibility; at the central level fisheries is the responsibility of the office of the Fisheries Development Commissioner (FDC) working under the Ministry of Food, Agriculture and Livestock (MINFAL). The office of the FDC is responsible for policy, planning and coordination with provincial fisheries departments and other national and international agencies. The Pakistan Agricultural Research Council (PARC) is the country's largest research organisation and is responsible to MINFAL. Some universities in the country are also involved in basic fisheries research.

About 13000 fish farms have so far been established across Pakistan, the size of these farms varies considerably, however, the average farm size ranges form 5-10 ha. No direct data on the number of fish farmers employed in this sector is available as fish farming in most parts of the country is carried out as an integral part of crop farming. According to a best estimates, about 50000 people are either directly or indirectly employed in the sector.
Pakistan has substantial areas of inland waters as a result of its location as the drainage basin for the Himalayas. The region between 33 o N and 20 o N consists of a network of rivers, canals, reservoirs, lakes, waterlogged areas and village ponds, etc. with a total area of about 8.6 million ha. Of this total, some 30000 ha correspond to the area utilized for cold-water trout production and other commercially important sport fishes such as mahseer (Tor tor) and snow trout (Schizothorax richardsonii).
About 110000 ha comprise the warm water natural lakes found in Pakistan of which the majority (101000 ha) are found in Sindh Province, which has a mix of both freshwater and saline lakes. In some of these saline lakes, the salinity levels are higher than sea water thereby limiting their potential for fisheries production.
While these resources possess great development potential to help meet the increasing demand for protein from the population, fish farming has never been a major economic activity neither have freshwater fish ever been a major food source for the inland population. The per capita consumption of fish products is currently around 1.9 kg which is amongst the lowest in the world.
The provinces with the greatest potential for development are Punjab, Sindh and to a lesser extent NWFP, the total number of farms in all provinces being approximately 13000. Although the fish farming through culture in ponds and other natural water bodies has been practiced for several decades, it is only during the last two decades that any impetus for further development can be seen with about 60470 ha of freshwater ponds being used for fish culture.
In Sindh Province, the majority of the farms are located in Thatta, Badin and Dadu, the three districts through which the River Indus passes. Badin and Thatta have water logged floodplain areas which are suitable for fish farming. In Punjab Province, farms are located mostly in irrigated areas or where there is abundant rain and the soil is alluvial. As a result, Sheikhpura, Gujranwala, and Attock districts have larger number of farms and constitute around three quarters of the total number of farms in Punjab.
The NWFP has comparatively fewer farms, because of the cold climate in the mountainous areas. Trout farms are located in Chitral, Swat, Dir, Malakand, Mansehra, Federally Administered Tribal Area (FATA) and other parts of NA. Carp culture is practiced in Dera Ismail Khan, Kohat, Mardan, Swabi and the Abbotabad districts of NWFP.
Inland fish farming is under the control of the provincial governments, who supply seed, operate hatcheries, provide extension services, collect primary data and promote fisheries through extension manuals, brochures and by arranging seminars, etc. Existing farming methods have not developed. However, as a result of a steady stream of newcomers to the sector, there is a slow but steady improvement in technology over time.
In the past, most fish farmers stocked their ponds only with indigenous species such as catla (Catla catla), rohu (Labeo rohita), mrigal (Cirrhinus mrigala) and common carp (Cyprinus carpio). More recently, two fast growing species, the grass carp (Ctenopharyngodon idellus) and silver carp (Hypophthalmichthys molitrix), have been introduced for culture under modern polyculture systems to increase the fish yield per unit area. These two species have good economic values; have gained a reputation and became popular amongst the producers as well as consumers. Two species of trout namely brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) are cultured in NWFP, AJK and NA.
The following organisms are suitable for culture in an aquatic body in addition to fishes.
1. Rana catesbiana 2. R. hexadactyla 3. R. tigrina
1. Penaeus mondon 2. P. indicus 3. P. carinatus 4. P. setiferus 5. Palaemon styliferus 6. Metapenaeus monoceros 7. M. brevicornis 8. M. ensis
1. Homarus americanus 2. H. vulgaris
1. Scyila serrata 2. Portunus trituberculatus 3. cancer products
1. Crassostrea madrasensis 2. C. angulata 3. C. commercialis 4. C. gigas 5. Ostrea edulis
1. Mytlius edulis 2. M. galloprovincialis
1. Sepia sabaculeata 2. Sepioteuthis sepioidea
Tuesday, 18 April 2017 18:13


    Father of Biology
    - Aristotle

    Father of Botany
    - Theophrastus

    Father of Zoology
    - Aristotle
    Father of Plant Physiology
    - Stephan Hales

    Father of Taxonomy
    - Carl Linnaeus

    Father of Genetics
    - G.J. Mendel

    Father of Experimental Genetics
    - Morgan

    Father of Bryology
    - Johannn Hedwig
    Father of Modern Cytology
    - Carl P. Swanson
    Father of Microscopy
    - Marcello Malpighi
    Father of Plant Anatomy
    - N. Grew
    Father of Flistology
    - Francis Bichet
    Father of Mycology
    - Micheli

    Father of Palynology
    - Erdtman
    Father of Eugenics
    - Francis Galton
    Father of Biochemical Genetics
    - Archibald
    Father of DNA Finger Printing
    - Garrod
    Father of Ethology
    - Jaffery Lorentz
    Father of Endocrinology
    - Addison
    Father of ATP Cycle
    - Lipmann
    Father of Stress Physiology
    - Hans Selye
    Father of Gerontology
    - Korenchevsk
    Father of Indian Ecology
    - R. Mishra
    Father of Comparative Anatomy
    - Bason George Cuvier
    Father of Modern Anatomy
    - Andreas Vesalium
    Father of Experimental Physiology
    - Galen
    Father of Study of circulation of Blood
    - William Harvey
    Father of Evolutionary ideas
    - Empedocles
    Father of Eugenics
    - F. Galton
    Father of Modern Embryology
    - K.V. Baer
    Father of Ayurveda
    - Charaka
    Father of Paleontology
    - L. da Vinci
    Father of Medicine
    - Hippocrates
    Father of Indian Mycology
    - E.J. Butler
    Father of Bacteriology
    - Robert Koch
    Father of Microbiology
    - Louis Pasteur
    Father of Mutation
    - Hugo de Vries
    Father of Special Creation Theory
    - Father Suarez
    Father of Immunology
    - Edward Jenner
    Father of Modern Genetics
    - Bateson
    Father of Blood Groups
    - C. Landsteiner
    Father of Genetic Engineering
    - Paul Berg
    Father of Biochemistry
    - Leibig
    Father of ECG
    - Einthoven
    Father of Conditioned Reflex
    - Pavlov
    Father of Polygenic Inheritance
    - Koireuter
    Father of Epidemiology
    - John Snow
    Father of Plant Pathology
    - Debary
    Father of Antiseptic Surgery
    - Joseph Lister
    Father of Antibiotics
    - Alexander Fleming
    Father of Radiation Genetics
    - H.J. Muller

One family of superbugs, known as carbapenem-resistant Enterobacteriaceae or CRE, may be spreading more widely than previously thought, according to a study published Monday in the journal Proceedings of the National Academy of Sciences. In fact, transmission of these bacteria person-to-person may be occurring without symptoms, say the researchers, from the Harvard T.H. Chan School of Public Health and the Broad Institute.

CRE, which tend to spread in hospitals and long-term care facilities, cause an estimated 9,300 infections and 600 deaths each year in the United States, according to the Centers for Disease Control and Prevention.

Wednesday, 05 April 2017 10:10


Objective: To test organism's ability to tolerate various osmotic concentrations.

Test Procedure
1. Use a sterile loop or needle to inoculate broth tubes with different salt concentrations.
2. Incubate at the optimum temperature for 48-96 hours.

• Interpretation
Positive = growth; Negative = no growth

Wednesday, 05 April 2017 09:45


Objective: To test the organism's susceptibility to antibiotic penicillin.

Test Procedure and Interpretation: See the Optochin Disc Test.

Discovery of Penicillin

The discovery of penicillin's antibiotic powers is attributed to Alexander Fleming. The story goes that he returned to his laboratory one day in September 1928 to find a Petri dish containing Staphylococcus bacteria with its lid removed.

The dish had become contaminated by blue-green mold. He noted that there was a clear ring surrounding the mold where the bacteria had been inhibited from growing.

This discovery of the mold - Penicillium notatum - and his recognition of its special powers set the wheels in motion to create one of the most used drugs in medical history.

In March 1942, Anne Miller became the first civilian to be treated successfully with penicillin having almost died from a huge infection following a miscarriage.

Although Fleming often gets the accolade for having invented the first antibiotic, there was a lot of work to do before penicillin could become as commonly used and useful as it is today.

The bulk of the work was eventually carried out by scientists who had a much better-stocked laboratory and a deeper understanding of chemistry than Fleming. Dr. Howard Florey, Dr. Norman Heatley, and Dr. Ernst Chain carried out the first in-depth and focused studies.

Interestingly, and with impressive foresight, Fleming's Nobel Prize acceptance speech warned that the overuse of penicillin might, one day, lead to bacterial resistance.

Objective: To determine the organism's oxygen requirement.

Test Procedure
1. Inoculate 5 ml of BHI broth with your unknown organism and incubate overnight. We have found that broth cultures provide much more accurate results than using inoculum from a plate. However, if you are inoculating from a plate, make sure you use a very light inoculum.
2. Obtain a thioglycollate tube and make sure that it does not have more than 20% of the medium in pink color. This may happen due to oxidation of the top layer of the medium. To restore anaerobic conditions, such a tube should be placed in boiling water for 10 minutes and then cooled to room temperature. If you do not see any pink color against a white background, the tube is good to use.
3. Use a sterile narrow thin needle (rather than a thick one), insert into your culture broth and slowly stab a thioglycollate tube to the bottom. Carefully remove the needle along the same stab line. Do not shake the tube or move the needle around, or you will introduce extra oxygen into the medium. The needle should reach all the way to the bottom of the tube.
4. Incubate the tube at 30°C (without any regard to the optimum temperature requirement of your species) for 24 hours before reading the tube.

• Interpretation
-- Aerobe: band of growth on the top of the tube. Some species have a tendency to grow very rapidly in thioglycollate tube so that the growth covers a rather thick band from the top and extends to the line of stab where there is oxygen available (brought in by the needle). So it is best to look at the bottom 1-cm of the tube and if it is clear with no growth whatsoever, then you can be sure that you have an aerobe.
-- Microaerophile: band of no growth at the top, then a band of growth extending a short distance down proceeded by no growth to the bottom. The bottom 3-cm of the tube should be clear of any growth.
-- Facultative Anaerobe: growth can occur either throughout the tube or can begin at some point below the surface and extend all the way to the bottom, even in the 1-cm bottom of the tube.
-- Anaerobe: growth only at the bottom fifth of the tube.

Wednesday, 05 April 2017 09:00


Objective: To determine the presence of the oxidase enzymes (e.g. cytochrome c oxidase).

Test Procedure and Interpretation
1. Grow the culture on a BHI plate for 48 hours. Up to 7 day old cultures are fine.
2. Warm the plate to 20-37°C. Pick a good amount of the test organism with a sterile swab and rub onto the reaction area of a DrySlide card. If the organism is oxidase positive, a purple color will develop on the slide within 20 seconds. The slide is saturated with Kovacs' oxidase reagent (1% N, N, N', N' tetra-methyl-p-phenylene diamine dihydrochloride). Oxidase negative colonies do not change the color of the slide in 20 seconds, or if they do, it would be after 20 seconds and thus negative.

• Precautions
-- Most Gram-positive bacteria and all Enterobacteriaceae are oxidase negative.
-- Do not attempt to perform an oxidase test on any colonies growing on media containing glucose, as glucose fermentation will inhibit oxidase enzyme activity, and result in possible false negatives. Oxidase test on Gram-negative rods should be performed only on colonies from nonselective and/or non-differential media to ensure valid results.
-- The culture should not be older than a week, unless the species is a slowgrower. False results may be obtained if the culture is old.
-- The oxidase reagent quickly auto-oxidizes (by free oxygen in the air) and loses its sensitivity. The reagent should be discarded if any precipitate forms. Avoid undue exposure of the reagent to light. The reagent must be made up fresh each week.
-- Time period for color development must be adhered to since a purpleblack color may develop later due to auto-oxidation of reagent and/or a weak positive oxidase organism containing a small quantity of cytochrome c oxidase.
-- As an alternative to Kovacs' reagent, one may use a few drops of a 1:1 mixture of 1% α−naphthol in 95% ethanol and freshly prepared 1% aqueous dimethyl-p-phenylenediamine oxalate.

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