What is the Complete Blood Count Test

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Sysmex machine for complete blood count test (CBC)?The complete blood count (CBC) is one of the most commonly ordered blood tests. The complete blood count is the calculation of the cellular (formed elements) of blood. These calculations are generally determined by special machines that analyze the different components of blood in less than a minute. A major portion of the complete blood count is the measure of the concentration of white blood cells,red blood cells, and platelets in the blood.White blood cell count (leukocyte count): The number of white blood cells (WBCs) in the blood. The WBC is usually measured as part of the CBC (complete blood count. There are different types of white blood cells, including neutrophils (polymorphonuclearleukocytes; PMNs), band cells (slightly immature neutrophils), T-type lymphocytes (T cells), B-type lymphocytes (B cells), monocytes, eosinophils, and basophils. All the types of white blood cells are reflected in the white blood cell count. The normal range for the white blood cell count varies between laboratories but is usually between 4,300 and 10,800 cells per cubic millimeter of blood. This can also be referred to as the leukocyte count and can be expressed in international units as 4.3 - 10.8 x 109 cells per liter. A low white blood cell count is called leukopenia. A high white blood cell count is termed leukocytosis. The machine generated percentage of the different types of white blood cells is called the automated WBC differential. These components can also be counted under the microscope on a glass slide by a trained laboratory technician or a doctor and referred to as the manual WBC differential. The hematocrit This is the proportion, by volume, of the blood that consists of red blood cells. The hematocrit (hct) is expressed as a percentage. Several methods exist for measuring hemoglobin, most of which are done currently by automated machines . Within the machine, the red blood cells are broken down to get the hemoglobin into a solution. The free hemoglobin is exposed to a chemical containing cyanide which binds tightly with the hemoglobin molecule to form cyanmethemoglobin. By shining a light through the solution and measuring how much light is absorbed (specifically at a wavelength of 540 nanometers), the amount of hemoglobin can be determined. Mcv: A standard part of the complete blood count, the mean cell volume (MCV) is the average volume of a red blood cell. This is a calculated value derived from the hematocrit and the red cell count (The hematocrit is the ratio of the volume of red cells to the volume of whole blood while the red cell count is the number of red blood cells in a volume of blood). The normal range for the mean cell volume is 86 - 98 femtoliters. Mean cell hemoglobin: The average amount of hemoglobin in the average red cell. The mean cell hemoglobin (MCH) is a calculated value derived from the measurement of hemoglobin and the red cell count. (The hemoglobin value is the amount of hemoglobin in a volume of blood while the red cell count is the number of redblood cells in a volume of blood.) The normal range for the MCH is 27 - 32 picograms. It is a standard part of the complete blood count.Mean cell hemoglobin concentration: The average concentration of hemoglobin in a given volume of blood. The MCHC is a calculated value derived from the measurement of hemoglobin and the hematocrit. (The hemoglobin value is the amount of hemoglobin in a volume of blood while the hematocrit is the ratio of the volume of red cells to the volume of whole blood.) The normal range for the MCHC is 32 - 36%. The MCHC is a standard part of the complete blood count. Red cell distribution width: A measurement of the variability of red blood cell size. Higher numbers indicate greater variation in size. The normal range for the red cell distribution width (RDW) is 11 - 15. The RDW is a standard part of thecomplete blood count.Platelet count: The calculated number of platelets in a volume of blood, usually expressed as platelets per cubic millimeter (cmm) of whole blood. Platelets are the smallest cell-like structures in the blood and are important for blood clotting and plugging damaged blood vessels. Platelet counts are usually done by laboratory machines that also count other blood elements such as the white and red cells. They can also be counted by use of a microscope. Normal platelet counts are in the range of 150,000 to 400,000 per 9 microliter (or 150 - 400 x 10 per liter). These values many vary slightly between different laboratoriesESRESR stands for erythrocyte sedimentation rate. It is a test that indirectly measures how much inflammation is in the body. However, it rarely leads directly to a specific diagnosis. The blood sample is sent to a lab. The test measures how fast red blood cells called erythrocytes fall to the bottom of a tall, thin tube.Methods of screening for G6PD deficiency rely on the conversion by G6PD of glucose-6-phosphate to 6phosphgluconate. If G6PD is present, NADP will be converted to NADPH, which then reduces a substrate to either a colored or fluorescent product. In G6PD deficiency, no colored or fluorescent product is detected. Results are reported as normal or deficient. The reference value is normal. Specimen requirement is one lavender top (EDTA) tube of blood.The Widal test is made to diagnoise Typhoid fever. procedure for widal tets is as follows. 1.Make a series of serum dilutions for each antigen to be tested. Include tubes with 0.5 ml saline for control ofeach antigen to be used. 2.Use perfectly clean and dry test tubes and prepare dilutions beginning with 1:10 and doubling through 1:320 or so. 3.Add 0.1 ml of serum to 0.9 ml of physiological saline and then dilute serially by mixing 0.5 ml diluted serum with 0.5 ml saline and discarding 0.5 ml from the last tube. 4.From specimen submitted to detect possible rise in titre, prepare a series of 10 dilutions, ending with 1:5120. In this way Widal test is performed.Principle The Widal test is applied for the diagnosis of enteric fever that includes typhoid and paratyphoid caused by Salmonella typhi and Salmonella paratyphi respectively. For the slide agglutination test, stained Salmonella antigens are used to detect the presence of specific agglutinin in the patients serum. The slide agglutination test is used as a primary screening procedure. There are some agglutinins that are produced in the patients serum during the fever period, which react with somatic antigen O of Salmonella typhi, A or B of Salmonella paratyphi and then with flagellar antigen H which is common in most of the Salmonella species. In this test four specific antigen suspensions are used viz H, Salmonella typhi (O antigen), Salmonella paratyphi - A and Salmonella paratyphi - B. If agglutination occurs in O antigen added circle, then it is considered positive for Salmonella typhi. If agglutination occurs in A or B antigen added circle, then it is confirmed as positive for paratyphoid. Agglutination will occur in H antigen circle for all the cases of antigens like O, A, and B. Materials required 1. Widal test kit 2. Widal test slide 3. Suspected serum sample 4. Pipette 5. Applicator stick Procedure 1. A clean glass marked with six circles was taken. 2. The circles were labeled as H, O, A, B, positive control and negative control from the first circle to the last. 3. One drop of undiluted serum was placed in the first four circles with the help of a sterile pasture pipette. 4. One drop of postive control serum and one drop of negative control serum was placed in the fifth and the last circle respectively.5. One drop of H antigen was added to the first circle and one drop of Salmonella typhi O antigen was added in the second circle. Salmonella paratyphi A antigen and Salmonella paratyphi B antigen were added in the third and fourth circles respectively. 6. One drop of H antigen was placed at the fifth circle and sixth circle. 7. With separate applicator sticks serum and the antigen was mixed together and was spread well to fill the whole of the individual circle. Then slide was observed for agglutination. Result: The given test patients serum is positive for typhoid. The given test patients serum is positive for paratyphoid A or B The given test patients serum is negative for typhoid and paratyphoid. -------------------------------------------------------------------------------------------------------------------(Draw and write in the left side of your observation note book) Obse[PRACTICAL 8]MTEB 2404RAPID PLASMA REAGIN (RPR) TEST.RPR Reactive Control: human serum containing 0.1% sodium azide as preservative. 3.RPR Non-reactive Control: human serum containing 0.1% sodium azide as preservative. Stabilized liquid control, non-reactive with RPR antigen. 4.Test cards and disposable pipette stirrers. PROCEDURE QUALITATIVE CARD TEST1.Bring the RPR carbon antigen suspension, controls and samples to roomtemperature. 2.Hold pipette stirrer in vertical position and dispense one drop of serum or plasma sample onto a separate circle on the test card with the disposable stirrer pipettes supplied. Use a fresh pipette stirrer for each sample.3.Use the flat end of the stirrer pipettes and spread the sample over theentire area of the test circle. Dispose of pipette stirrer. Repeat procedure for number of specimens tested. 4.Shake the carbon antigen suspension dispensing bottle prior to use. Place one (1) drop (20ul) of "free falling" antigen suspension onto test circle containing the sample. DO NOT MIX the sample and the antigen. 5.Place test card on an automatic rotator and rotate for 8 minutes at 100 r.p.m. 6.Read results macroscopically under a high intensity incandescent lamp or strong daylight. RESULTSQualitative Test1.Negative Reactions: Formed of milky suspension by comparing theRPR negative controlUrinalysis is an important tool in disease detection, as well as monitoring and screening animal health. Abnormalities can be indicative of diseases of the urinary system as well as other organ systems, including liver function, acid-base status, and carbohydrate metabolism.1 Complete urinalysis involves both macroscopic and microscopic assessment. This is typically performed by gross visual assessment of the urine, microscopic examination, and chemical evaluation. Several chemical parameters can be measured using a commercially available in house dipstick test. This test is relatively inexpensive, and takes less than 5 minutes to complete. Typical dipstick strips include the following tests: bilirubin, blood, glucose, ketones, pH, protein specific gravity, and urobilinogen. Some dipsticks also include leukocytes and nitrite analyses.Dipsticks may be removed from the air tight, light sealed containers. It is important not to touch the reagent areas of the strip as this may alter test results. Each reagent area should be immersed in urine by dipping. The excess urine should be removed to prevent dilution of reagents or mixing of reagents between pads. This can be achieved by tilting the strip and allowing the urine to run off the edges (Figure 2). While blotting excess urine, ensure the chemicals from the different tests do not mix.6Interpretation of Test Results Dipsticks commonly include tests for specific gravity, pH, glucose, protein, blood, bilirubin, ketones, urobilinogen, nitrite, and leukocytes. Specific Gravity Urine specific gravity is based on the ratio of weight of urine to weight of an equivalent volume of pure water. This test is used to measure tubular function. The dipstick measures specific gravity by measuring the change in pKa of polyelectrolytes in relation to ionic concentration5. Although dipstick strips do have a method of approximating specific gravity, this measurement is best made with a refractometer.1 Urine specific gravity measured by the dipstick can be falsely elevated by moderate to high concentrations of protein. Low reading may occur if the urine is alkaline.6 High lipid content in urine may also alter the results by either raising or lowering the specific gravity measurement.pH The pH of urine can vary depending on an animals diet as well as its acid-base status. For example, animals that primarily eat high protein meat-based diets will have acidic urine. On the other hand, animals that eat more vegetable-based diets will have an alkaline urine.1,5 Dipsticks measure pH using methyl red, bromthymol blue or phenolphathalein indicator dyes. These reagents react rapidly and result in a color change. pH can be approximated within 0.5 units using a dipstick. The urine sample should be fresh as urine becomes more alkaline on standing due to the conversion of urea to ammonia by bacteria (if present), and loss of CO2.1 Causes of acidic urine include: meat diet, systemic acidosis, hypochloridemia, and administration of acidifying agents such as d,l-methionine or NH4Cl. 4,5 Urine with high concentrations of glucose may have a lower pH.6 This is due to bacterial metabolism of glucose and and production of ammonia which lowers pH.1 Causes of alkaline urine include: vegetable based diet, bacterial infection of urease-producing bacteria, systemic alkalosis, urine exposed to room air for an extended time (loss of CO2), and administration of alkalinizing agents including citrate or NaHCO3.1,4,5 Urine pH also may provide good predictive assessment of crystal and stone morphology as certain crystals and stones form in either acidic or alkaline environments. Uric acid, cystine, and calcium oxalate crystals are found in acidic urine. On the other hand, struvite, calcium carbonate, calcium phosphate, ammonium biurate, and amorphous phosphate crystals are found in alkaline urine.5 For a more accurate assessment of urine pH, a pH meter may be used. However, for most routine veterinary analyses a dipstick pH reading is sufficient.5 Glucose Glucose is not detectable in the urine of healthy dogs or cats. In a healthy animal, glucose passes freely through the glomerular filter and is resorbed by the proximal tubules. If glucosuria is present, it is due to either an excess amount of glucose reaching the tubules that cannot be resorbed or, less commonly, decreased tubular resorptive function.4 Reagent strips measure glucose levels using the glucose oxidase method.1 This method is a sequential enzymatic reaction. Glucose reacts with glucose oxidase to produce hydrogen peroxide, which oxidizes the indicator chemical to produce a color change. The color change is related to the amount of glucose present in the urine sample (y Sample preparation 1. Obtain fresh urine sample 2. Centrifuge 10-15 ml at 1500 to 3000 rpm for 5 minutes 3. Decant supernatant and resuspend remainder of urine4. Place 1 drop of urine on slide and apply cover slip y Examination 1. Urine Cells 1. Urine White Blood Cells 1. Normal 50% 6. Normal sperm morphology: >14% strictly normal 7. White Blood Cells 48 million per ml 2. Initial sperm motility: >63% 3. Normal sperm morphology: >12% 6. Interpretation: Findings suggestive of Infertility 1. Sperm count (concentration):


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