Enzyme histochemistry of avian bone marrow and QCE6 cells.

MeC cultures of either quail bone marrow HPCs (A-B) or QCE6 cells (C-F) were cultured for 6 days, cytospun onto microscope slides, and assayed for leukocyte-associated enzyme activities. Representative staining for quail bone marrow cultures is shown for both AP (A) and NaF-resistant ANAE (B) activities. (A) All bone marrow–derived leukocytes were AP positive (reddish brown stain). (B) NaF pretreatment of bone marrow cultures distinguished macrophages, which remained ANAE positive (arrow), and the now ANAE-negative monocytes (arrowhead). (C) Similarly to bone marrow cells, all leukocytes that developed from QCE6 cells exhibited positive AP activity (reddish brown stain). (D) High levels of TARP activity were limited to QCE6-derived macrophage subpopulations (arrows). In contrast, tartaric acid treatment significantly reduced staining of monocytes (asterisk). (E) Naphthol AS-D CAE activity (brown stain) was exhibited by leukocytes of QCE6-cell origin. (F) As was shown in panel B with bone marrow cells, NaF pretreatment of QCE6 cells selectively inhibited ANAE activity to allow macrophages (brown stain; arrows) to be distinguished from unstained monocytes (arrowheads). For all these enzyme activities, the patterns of enzyme distribution were identical within cultures derived from either bone marrow or QCE6 cells. Scale bar: A, C, F, 10 μm; B, 12 μm; D, 5 μm; E, 11 μm.