• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

OBJECTIVES: To determine the fragility of the erythrocyte membrane against the hemolytic effect of NaCl solutions of varying concentrations

Extracts from this document...

Introduction

´╗┐PRACTICAL 4: OSMOTIC FRAGILITY OBJECTIVES: To determine the fragility of the erythrocyte membrane against the hemolytic effect of NaCl solutions of varying concentrations. INTRODUCTION: Osmosis is the diffusion of a solvent through a semi-permeable from a region of low solute concentration to a region of high solute concentration. The semi-permeable membrane is permeable to the solvent, but not to the solute, resulting in a chemical potential difference across the membrane which drives the diffusion. That is the solvent flows from the side of the membrane where the solution is weakest to the side it is strongest, until the solution on both sides of the membrane is the same strength (that is, until the chemical potential is equal on both sides). Red blood cells are bound by a membrane, which allows water to pass through while generally restricting the solutes. This process called osmosis, causes cells to shrink due to loss of water when in a hypotonic medium. This results in swelling and ultimately haemolysis as the cell bursts. The osmotic fragility test uses this fact to determine the concentration of solute inside the cell by subjecting it to the hemolytic effects of solutions of different concentrations. MATERIALS: 1. Ten test tube of NaCl (0.85%, 0.75%, 0.65%, 0.55%, 0.50%, 0.40%, 0.35%, 0.20%, 0.10% and 0%) 2. Distilled water 3. Blood 4. ...read more.

Middle

Therefore molarity of NaCl is equal to percentage of NaCl solution times 10 divide by RMM of NaCl solution. Concentration of NaCl Percentage of Haemolysis 0.15 0 0.13 2 0.11 11 0.09 14 0.08 31 0.07 79 0.06 85 0.03 92 0.02 96 0.00 100 *Graph should be Concentration of NaCl Vs Percentage of haemolysis Figure: Osmotic fragility curve (concentration of NaCl VS percentage of haemolysis) DISCUSSION: The osmotic fragility test measures the ability of red blood cells to retain their integrity in hypotonic solutions. A solution is hypotonic if its salt concentration is lower than that found in the blood, about 0.9% by weight. The test uses around 10 different hypotonic solutions varying in salinity from 0.1% to 0.9%. Each solution has a small amount of blood added to it. In a hypotonic solution, a red blood cell takes in water, lowering the salinity in the cell until it matches the salinity of the solution. This happens through the process of osmosis. Osmosis is the movement of solvent across a membrane from a lower concentration to a higher concentration. Figure: osmosis occurs on red blood cell. In this case, the solvent is water, the membrane is the membrane of the red blood cell and the concentration of salt in the solution is lower than the concentration in the cell. ...read more.

Conclusion

Recommend testing during a state of prolonged homeostasis with stable hematocrit. Figure: osmotic fragility test. Osmotic fragility of red cells increased in: 1. Hereditary spherocytosis. 2. Acquired spherocytosis. Osmotic fragility decreased in: 1. Thalassemia. 2. Iron deficiency anemia. 3. Sickle cell anaemia. QUESTION: 1. A test tube with blood in it has a particular solution added to it. After several minutes, the solution is not clear anymore, but becomes red. Which solution was added to the blood to obtain this result? 1. 0.9% saline 2. 5% saline 3. Distilled water 1. A 0.8% saline solution would be __________ to the cytosol of a cell. 1. Hypotonic 2. Hypertonic 3. Isotonic 1. If you placed a peeled apple or potato in 5% salt solution, it would: 1. Gain weight 2. Lose weight 3. Stay the same weight CONCLUSION: Osmotic fragility test is a test that measures the resistance to haemolysis of red blood cells (RBC) exposed to hypotonic solutions. RBC is exposed to a series of saline (NaCl) solutions with increasing dilution. The sooner haemolysis occurs; the greater is osmotic fragility of RBC. RBC remains same because it same as RBC concentration, Isotonic solution ? 0.9 % NaCl. RBC burst in hypotonic (< 0.9 % NaCl), and shrink (crenate) in hypertonic solutions (> 0.9 % NaCl). In hypotonic medium a membrane rupture occurs, allowing haemoglobin to exit from the cells. By measuring haemoglobin concentration, the percentage of haemolysis at different NaCl concentrations can be calculated. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our University Degree Applied Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related University Degree Applied Biology essays

  1. Effect of exercise on heart rate and arterial blood pressure in young healthy volunteers.

    This is what we know as blood pressure. The results of this study are consistent with other research literature [1][2][3][4][5] and it can be concluded that, systolic blood pressure does indeed increase according to increased physical activity and increased heart rate.

  2. Effect of Isotonic Exercise on HR and BP

    is greater and resistance is reduced as friction has also been reduced. This is known as vasodilation. In contrast when contraction of the smooth muscle occurs, the diameter of the blood vessel has been reduced and there is an increase in both friction and resistance. This is known as vasoconstriction.

  1. Experiment on Spectrophotometer

    Purity of Cytochrome c: 0.661 x 100 = 70.46 % 0.938 Conclusion The aim of the experiment was to determine the light absorbed by the solution, hence it was achieved as the results show the amount of absorption at different wavelength, the peak absorption

  2. This experiment was carried out to separate and characterize the protein mixture which contained ...

    KCl has a higher ionic strength than the MES od histidine buffer. As a result, KCl will bind to the resin easier and elute the bound haemoglobin or serum albumin. Also, coomassie blue reagent was used as a dyeing agent in determination of serum albumin.

  1. Superbugs the rise and fall of hospital acquired infections

    Recent data from the Health Protection Agency show that cases fell by 4.3% between 2005 and 2006 and believe it has now reached a plateau (Star, 2007). Despite this there is still the belief that infection rates remain high and not enough is being done for prevention.

  2. Isolation &amp;amp; Characterisation of Proteins. The purpose of conducting this experiment is to ...

    Based on figure 1, sample C has the greatest distance migrated followed by sample B and A. This is because sample C has the lowest protein mixture concentration with dilution factor of 50, which means among all three samples with equal volume of sample, sample C has the least amount of protein mixture present in the solution.

  1. Food Science -Experiments to Determine the Properties and Uses of Enzymes in Food Preperation.

    Functions According to Aurand (1973), polyphenol oxidase catalyzes two basic types of reactions, hydroxylation and oxidation. In hydroxylation, Cu+ is oxidized to Cu2+. It occurs on phenols containing only one hydroxyl group while oxidation has been defined as a loss of electrons in an atom or simply chemical combination with oxygen (Vieira, 1999).

  2. Regional anatomy - case studies of the spinal region

    The nerve is then traverses the posterior triangle obliquely to innervate the trapezius muscle, which is the only muscle that can elevate the tip of the shoulder (the acromion). Typically, the sternocleidomastoid is normal, since the injury is to the nerve after the branch to the SCM has originated.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work