A slide section may show uneven staining with hematoxylin and eosin if certain conditions are present.
Criteria: intensity of staining with hematoxylin and/or eosin differs within the section
Causes:
(1) variation in section thickness
(2) one or both of the stains may not have covered the section evenly
(3) the water rinsing step after the hematoxylin stain may not have been adequate
(4) the water rinsing step after acid-alcohol step was inadequate
(5) the water rinsing step after the bluing step was inadequate
(6) the alcohol rinsing steps after the eosin stain were inadequate
(7) the hematoxylin stain had settled out, creating a gradient
Corrective actions:
(1) make sure sections are uniform at the desired thickness
(2) make sure that each stain is well mixed and that each covers the section
(3) make sure that rinsing steps are performed properly
