Which fixative is used for hematopoietic (bone marrow) and lymphoreticular (lymph node, spleen) tissue and demonstrates good nuclear detail, staining, antigenicity?

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Fixatives differ in how they preserve cellular detail and antigens; for bone marrow and other lymphoid tissues you want crisp nuclear detail while keeping epitopes accessible for immunostaining. B5 is an ethanol-based fixative with picric acid, which fixes proteins gently and preserves antigenicity better than harsher crosslinking fixatives, while still delivering sharp nuclear and cytoplasmic detail. This combination makes it especially suitable for hematopoietic and lymphoreticular tissues, where identifying cell types and performing antibody staining is important. Bouin's gives excellent morphology but can mask antigens and leaves a yellow background from picric acid; Carnoy's fixes with alcohol and acetic acid, causing distortion and poorer antigen preservation; Zenker's uses toxic heavy metals and can also mask antigens. So B5 best meets the need for good nuclear detail, staining quality, and antigen detection in these tissues.