A Quick-Reference Tool for Hemolysis Status
Hemolysis is the breakdown of red blood cells, which can have an effect on laboratory results. Serum samples containing more than 100 mg/dL of hemoglobin can cause non-specific binding in serologic tests. Therefore, serologic testing is not recommended for a serum sample containing more than this amount of hemoglobin.
Knowing the hemolysis status of a serum sample before testing can save time and resources. CDC’s Division of Vector-Borne Diseases created a quick-reference “Hemolysis Reference Palette” for laboratorians and phlebotomists to use when the hemolysis status of a sample is in question.
Create a Hemolysis Reference Palette
- Print the palette from a color printer. Be sure to mark “Print on Both Sides.”
- Cut out the palette with scissors by cutting along the dotted line.
- Laminate the palette.
- Place palette(s) around the laboratory for easy access:
- Glue a magnet on the back, or
- Punch a hole at the top and hang from a hook.
How to Use the Palette
- Place serum sample on a white background.
- Compare color tabs on the palette to the serum sample.
- Determine the sample quality using the color referenced on the palette.
- Serum samples that match colors with 100 mg/dL or darker should not be processed by serology testing.
Prevention of hemolysis is important to preserve the quality of a serum sample for testing.
Best Practices to Prevent Hemolysis
- Use the correct needle size for blood collection (20-22 gauge).
- Avoid using butterfly needles, unless specifically requested by patient.
- Warm up the venipuncture site to increase blood flow.
- Allow disinfectant on venipuncture site to dry completely.
- Collect blood sample in the correct blood collection tube (red cap/tiger tube = without anticoagulants).
- Collect the correct volume for the tube size. Use smaller tubes for difficult draws.
- Coagulation: place the tube in an upright position for 15-30 minutes at room temperature. Then store at 4°C.
- Centrifuge samples for serum separation within 4 hours of sample collection.
- If tests are performed within 48 hours of collection, transfer serum to a sample tube (cryovial) and store at 4°C.
- If tests will be performed more than 48 hours after collection, aliquot samples and store at -20°C or lower.