Methylcellulose cultures clotted and stained for permanent record.

Whereas methylcellulose cultures have been valuable for biochemical studies on hemopoiesis in vitro, it has been difficult to study cellular morphology in these cultures. We have found that clotting factors can be added at any time during the culture period and non-adherent cells become entrapped in a semisolid clot. The clot can be removed, fixed and stained for detailed microscopic examination.