The sugar-water hemolysis test is a blood test to detect fragile red blood cells by testing their ability to withstand swelling in a low-salt solution.
Alternative NamesSucrose hemolysis test
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.
The blood sample is sent to a laboratory to be tested. When a low-salt solution containing sucrose (sugar) is added to certain fragile cells, a part of the body's defense mechanism called complement is activated, binds to the cells, and bursts them.
How to prepare for the testThere is no special preparation needed 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 performedYour doctor may order this test if you have signs or symptoms of paroxysmal nocturnal hemoglobinuria (PNH) or hemolytic anemia of unknown cause. PNH red blood cells are very likely to be harmed by the body's complement system.
Normal ValuesNote: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results meanThere is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
A negative test does not rule out PNH. False-negative results may occur if the fluid part of blood (serum) lacks complement.
ReferencesSchwartz R. Autoimmune and intravascular hemolytic anemias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 164.
Brodsky RA. Paroxysmal nocturnal hemoglobinuria. In: Hoffman R, Benz EJ, Shattil SS, et al, eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 30.
Reviewed ByReview Date: 03/21/2010
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
One test to differentiate between Micrococcaceae and Streptococcaceae is the catalase test. Micrococcaceae are catalase-positive, producing bubbles when hydrogen peroxide is added, while Streptococcaceae are catalase-negative, showing no bubbles. Another test is the hemolysis pattern on blood agar plates – Micrococcaceae typically exhibit gamma hemolysis (no hemolysis), while Streptococcaceae may show alpha or beta hemolysis.
Proteus vulgaris is a bacterium that shows beta hemolysis on blood agar plates. In the Blood Hemolysis Test, this means that Proteus vulgaris will cause complete lysis of red blood cells, resulting in a clear zone around the bacterial growth on the agar plate.
Yes, blue top tubes can cause hemolysis if they are shaken too vigorously during blood collection. Hemolysis can release hemoglobin from red blood cells into the serum, affecting test results. It is important to follow proper blood collection techniques to prevent hemolysis.
Icterus, Hemolysis, or Lipemia interfere with reading the color change
Hemolysis can falsely increase CO2 values in blood samples because red blood cells release CO2 when they are broken down. This can interfere with accurate measurement of CO2 levels in the blood. It is important to differentiate between true changes in CO2 levels and those caused by hemolysis when interpreting test results.
Hemolysis can significantly affect a bilirubin test by falsely elevating the results. When red blood cells break down, they release hemoglobin, which is then converted to bilirubin. If a sample is hemolyzed, the increased levels of free hemoglobin can lead to an overestimation of total bilirubin, particularly the unconjugated fraction, potentially leading to misdiagnosis or inappropriate treatment. Therefore, it's essential to avoid hemolysis during sample collection and handling for accurate bilirubin measurement.
Alpha hemolysis (α-hemolysis) means that the bacterial enzymes only partially break down the blood cells. This results in the media showing a yellowish/greenish/brownish discoloration (like a bruise) around the colonies, indicating incomplete hemolysis.How to Interpret Beta Hemolysis on Blood Agar: Test for Strep Throat - Identifying B-hemolytic Streptococcus
Partial hemolysis in blood samples refers to the breakdown of some red blood cells, leading to a pink or red discoloration of the sample. This can affect the accuracy of certain blood tests, as it may release substances that interfere with the results. It is important to properly handle and store blood samples to prevent hemolysis and ensure reliable test results.
An indirect Coombs' test looks for antibodies to someone else's red blood cells in the patient's serum
Clinically significant hemolysis is rare problem but it can affect red blood cell count and density of plasma. Studies have been done about the effect of hemolysis on hematocrit and the results stated that the changes appear too small to be accurately detected.
A red color in the serum of a serum separator tube (SST) may indicate hemolysis, which is the rupture of red blood cells and release of hemoglobin into the serum. Hemolysis can affect certain laboratory test results and may require a new blood sample to be collected for accurate testing.
No, the Gram stain is primarily used to differentiate bacteria based on their cell wall structure (Gram-positive vs. Gram-negative). Hemolysis is a test used to determine the ability of bacteria to lyse red blood cells, which can provide information on the pathogenicity of the organism.