Cresyl Information and Courses from MediaLab, Inc.
These are the MediaLab courses that cover Cresyl and links to relevant pages within the course.
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| A brilliant cresyl blue stain was performed on this patient's sample. How should this stain be interpreted? | View Page |
| Repeat Hemoglobin Electrophoresis After considering the results of the brilliant cresyl blue stain, the clinical laboratory scientist decided to repeat the hemoglobin electrophoresis on this patient. This time, she shortened the electrophoresis time by fifteen minutes.The results of the electrophoresis, represented in the image below, show a band in the area of Hb H. Hemoglobin H travels quickly during alkaline electrophoresis, and a shorter electrophoresis time was needed to ensure that HbH remained on the acetate paper. HbF is still present as it was on the original electrophoresis, but it is blended into the Hb A band. | View Page |
| Brilliant Cresyl Blue stain Hemoglobin H, consisting of beta chain tetramers, is an unstable hemoglobin which forms precipitates just below the cell's membrane and can be observed when red blood cells are stained with Brilliant Cresyl Blue (BCB). | View Page |
| Match the images of these cells stained with Brilliant Cresyl Blue with the appropriate description. | View Page |
| Reticulocytes Although the nucleus has been extruded, the reticulocyte is still considered immature because it retains numerous organelles needed for hemoglobin production, such as ribosomes, mitochondria, and fragments of the Golgi apparatus. The reticulocyte is slightly larger (10 microns) than the mature erythrocyte. A reticulocyte normally remains in the bone marrow for one or two days before entering the circulation and its final 24 hours of maturation. The red cell is mature when hemoglobin production is complete and the organelles have disintegrated. Reticulocytes normally make up 0.5 - 1.5% of the peripheral blood red cells. They appear blue/gray on the Wright's stained smear. The residual RNA in the cytoplasm causes the blue/gray color. The terms, polychromasia or polychromatophilic, are used to describe these cells on a Wright's stained preparation. A supravital stain such as new methylene blue N or brilliant cresyl blue is used to stain reticulocytes for an actual count. | View Page |
| Heinz body formation Heinz bodies are 1-3 um particles of denatured hemoglobin settling eccentrically, usually close to the red cell membrane. They are found in erythrocytes in unstable hemoglobin disorders, acute drug induced hemolysis, and following splenectomy. Their formation may be exaggerated by in-vitro incubation of a fresh blood sample with phenylhydrazine. Heinz bodies, as pictured here, are identified using a supra-vital stain, such as new methylene blue or cresyl violet. Bite cells, visible with Wright-Giemsa staining, are visual reminders that the spleen is functional and has pitted the aberrant chunk of hemoglobin from the circulating erythrocyte. | View Page |
| Hemoglobin H disease Hemoblobin H disease follows deletions of 3 of the 4 alpha globulin chains. Beta chains, unable to bind with insufficient numbers of alpha chains, form beta chain tetramers, or HbH.These beta chain tetramers appear as numerous dot size inclusions in erythrocyte cytoplasm, best seen in supravital brilliant cresyl blue stains (lower photograph).The most common molecular defect in alpha thalassemia is DELETION, not MUTATION; whereas, in beta thalassemia, the molecular defect is MUTATION.Leptocytes, as illustrated in the upper photograph,(lepto, derived from a Greek word meaning thin, fine, or slight), are characteristic of HbH disease. They have thinner cell membranes than the cells we recognize as target cells. They stain more lightly than normal erythrocytes and their centers are almost colorless.Subtle changes perhaps, but worth keeping in mind | View Page |
| The patient, an 8-month-old girl, was anemic, jaundiced, and had splenomegaly. Her family had immigrated from the Middle East. Based on the history and the peripheral blood picture, the most probable diagnosis is thalassemia. | View Page |