Effect of pH Value Changes in Ehrlich Haematoxylin Staining Solution on the Staining of the Tissue Slices

Objective To investigate the effects of pH value changes in Ehrlich haematoxylin staining solution on the tissue staining and to discuss techniques to improve the quality of HE staining.Methods Ehrlich haematoxylin staining solution was treated with 2 mol/L NaOH solution and 2 mol/L HCl solution respectively,then pH values were determined.The tissue staining effects at different pH values in Ehrlich haematoxylin staining solution were observed.Results The karyon of the tissue slices in low pH values staining solution was blue or navy blue,clearly against its background,and the staining of karyon and cytoplasm contrasted sharply without any haematoxylin residues clung to the tissue slices;on the other hand,the karyon of the tissue slices in high pH values staining solution was grey blue or purple black,not clearly agaisnt its background,and the staining of karyon and cytoplasm contrasted hazily,with many haematoxylin residues clung to the tissue slices.Conclusion The changes of pH value in Ehrlich haematoxylin staining solution have great effect on the HE staining of the tissue slices,and keeping the pH value of staining solution in a low level can improve the quality of HE staining.