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Osmotic fragility is a test to detect whether red blood cells are more likely to break down.
How the test is performedBlood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
In the laboratory, red blood cells are tested with a solution that makes them swell, in order to determine how fragile they are.
How to prepare for the testNo special preparation is necessary for this test.
How the test will feelWhen the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performedThis test is performed to detect hereditary spherocytosisand thalassemia. Hereditary spherocytosis makes red blood cells more fragile than normal. Some red blood cells in patients with thalassemia are more fragile than normal, but a larger number are less fragile than normal.
Normal ValuesA negative test is normal.
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results mean- Thalassemia
- Hereditary spherocytosis
Veins and arteries vary in size from one patient to another, and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Golan DE. Hemolytic anemias: red cell membrane and metabolic defects. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 165.
Gallagher PG, Jarolim P. Red Blood Cell Membrane Disorders. In: Hoffman R, Benz EJ, Shattil SS, et al, eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 46.
What else can I help you with?
What are the different methods used for osmotic fragility test?
-Acidified glycerol Lysis test - the Pink Test - NESTROFT ( naked eye single tube red cell osmotic fragility test ) :) - i tried to search this and i guess this would help other medtech students and to anyone related to it :) by: Peter Paul M. Pastor heheee!! XD
How do osmotic saline laxatives work?
Osmotic saline laxatives work by drawing water into the intestines through osmosis, which softens the stool and increases its volume. This stimulation helps to promote bowel movements and alleviate constipation.
Which of the following solutions has the highest osmotic pressure?
The solution with the highest concentration of solute particles will have the highest osmotic pressure.
How can one determine the osmotic pressure of a solution?
To determine the osmotic pressure of a solution, you can use the formula: iMRT, where is the osmotic pressure, i is the van't Hoff factor, M is the molarity of the solution, R is the ideal gas constant, and T is the temperature in Kelvin. By plugging in the values for these variables, you can calculate the osmotic pressure of the solution.
How do you calculate osmotic pressure in a solution?
Osmotic pressure in a solution is calculated using the formula: iMRT, where is the osmotic pressure, i is the van't Hoff factor, M is the molarity of the solution, R is the gas constant, and T is the temperature in Kelvin.
What does low osmotic fragility means?
Osmotic fragility usually (unless otherwise mentioned) refers to the ease with which Red Blood Cells (RBCs) undergo lysis in a hypotonic solution. Before knowing what 'low osmotic fragility' means, one should know the concept of osmotic fragility. Different parameters, some of them related to the RBC and some of the extracellular environment have an effect on osmotic fragility. Low osmotic fragility means that the RBCs have a resistance against undergoing lysis when suspended in solutions which are hypotonic. They undergo lysis only if the solution is extremely hypotonic. In contrast, high osmotic fragility refers to the tendency of the RBCs to lyse even if the solution in which they are suspended in is mildly hypotonic. As an example for low osmotic fragility would be thalassemia. And as an example for high osmotic fragility, spherocytosis (a hereditary condition where the RBCs lose their usual biconcave structure and become spherical) causes increased osmotic fragility. i.e, It very easily lyses even at solutions which are mildly hypotonic... p.s Another interesting point to note is that in sickle cell anemia, the RBCs show increased mechanical fragility but decreased osmotic fragility. Elucidated by the fact that post-splenectomy the RBC lifespan increases.
Why does osmotic fragility curve have a sigmoidal curve?
The osmotic fragility curve has a sigmoidal shape because red blood cells undergo a gradual increase in fragility as the osmolarity of the surrounding solution increases. Initially, there is little change in fragility as osmolarity increases, followed by a sharp rise in fragility at a certain point, and then a plateau as the cells reach their maximum fragility.
Why does osmotic fragility has sigmoid shape?
the cell respon differently to different solution
What factors affect osmotic fragility tests?
Factors that affect osmotic fragility tests include the pH of the solution, temperature, duration of exposure to hypotonic solutions, and the presence of any interfering substances in the sample. Changes in these factors can alter the erythrocyte membrane permeability and impact the results of the test.
What is osmotic alterations?
Osmotic alterations can be defined as the fragility of the red blood cells in hypo and hyperthyroid patients. Changes in the concentration of the thyroid hormone can affect Na+K+ATPase number and activity and the phpspholipid composition of the cell membranes.
What are the different methods used for osmotic fragility test?
-Acidified glycerol Lysis test - the Pink Test - NESTROFT ( naked eye single tube red cell osmotic fragility test ) :) - i tried to search this and i guess this would help other medtech students and to anyone related to it :) by: Peter Paul M. Pastor heheee!! XD
How do you determine Iso-osmotic concentration?
Iso-osmotic concentration refers to a solution that has the same osmotic pressure as another solution. To determine iso-osmotic concentration, you can use colligative properties such as freezing point depression or osmotic pressure measurements. By comparing these values between solutions, you can identify when two solutions have equal osmotic pressure and thus have iso-osmotic concentration.
What is the osmotic coefficient of NaCl?
The osmotic coefficient of sodium chloride is 0,93.
What is the meaning of osmotic?
Pertaining to, or having the property of, osmose; as, osmotic force.
In which direction does water move in a solution when there is a difference in osmotic pressure, from low to high?
In a solution with a difference in osmotic pressure, water moves from an area of low osmotic pressure to an area of high osmotic pressure.
What is an osmotic conformer?
An osmotic conformer is an organism that maintains its internal osmotic pressure to match its external environment. This allows the organism to prevent excessive water loss or gain in response to changes in the salinity of its surroundings. Osmotic conformers are typically found in environments with stable osmotic conditions.
What is it called when cells burst because of osmotic pressure?
Cytolysis or Osmotic-lysis
