Metachromatic Globules in the Degenerated Brilliant Cresyl Blue Stain Proved to be Fibronectin

Kim, Ae Seek; Cho, Han Ik; Park, Sung Sup; Kwon, So Yong

Abstract

BACKGROUND: We incidentally found purple metachromatic globules looked like red blood cells in the blood smears of a leukemic patient for reticulocyte count. The metachromatic globules were various in size and shape. The stain solution of brilliant cresyl blue was degenerated to pH change of 3.5. To find out the nature of these metachromatic globules, this study was performed.
METHODS
Reticulocyte count stain was performed on the slide smears with EDTA bloods, their plasma, and sera of leukemic patients and normal persons using the degenerated brilliant cresyl blue stain solution. To clarify the nature of the metachromatic globules, we also carried out immunocytochemical stain with monoclonal antibodies to fibronectin and fibrinogen on the same slide smears prepared. The pH of the stain solution checked.
RESULTS
EDTA blood, plasma and human fibrinogen product showed the same metachromatic globules. But in serum smear the metachromasia was faint and globule shape was not noted. Purified human fibrinogen showed reticulated pattern metachromasia. Immunocytochemical stain with monoclonal antibody to the fibronectin showed small dot, round, budding, and globule form positivity in the smear of EDTA blood, plasma, and human fibrinogen product. Platelets also showed positive reaction. Purified human fibrinogen showed no positive reaction. Immunocytochemical stain with monoclonal antibody to the fibrinogen on the other hands showed reticulated pattern positivity in EDTA blood, plasma, human fibrinogen product and purified human fibrinogen. Smear with serum showed no positive reaction. The stain solution was degenerated to acidic pH of 3.5.
CONCLUSIONS
Fibronectin, ubiquitous adhesive protein, was easily observed by simple stain method. Further study should be followed, however we suggest detection of plasma fibronectin which is costly, could be easily done by simple stain method.