The dual-rotary circumfusion system for Mark II culture chambers: I. Design, control, and monitoring of the system and the cultures

Abstract

A modification of the 12-chamber circumfusion system (Rose, 1967) is described as a dual unit for the rotation of 24 Mark II culture chambers and the circulation of 1000 ml of oxygen-saturated nutrient through each chamber at a rate of 5.5 ml/min. The fluid nutrient may be directed through 6- or 12-chamber subsystems or recombined into 12- or 24-chamber super systems by fluid-switching devices. The rotation of the chambers (2 or 5.5 rpm) prevents sediments from being deposited on the cover slips and effects an alternating intrachamber hydrostatic pressure analogous to in vivo venous and arterial capillary pressures (18–32 ± 3 mm Hg). Pulsation rates of 66 or 132 pulses/min and a pulse pressure of 1–5 mm Hg may be induced or deleted. The cultures are established under sheets of dialysis cellophane on the glass cover slips of the new Mark II multipurpose culture chambers. The new design of these chambers prevents a wrinkling of the cellophane, and with the improved sustaining features of the dual-rotary units creates an environment for the progression and maintenance of differentiation of cultured fetal tissues which is much superior to that of the previously described circumfusion system. Examples of the morphological differentiation observed in fetal rat ovary and thyroid and the longevity of their differentiated appearance are reported.