Oxygenation of tissues, especially cardiac muscle, is a requisite in maintaining normal physiological and biochemical responses. However, aeration can introduce mechanical noise due to impinging of gas bubbles on the suspended tissue. This mechanical noise can obscure the force measurements collected from small tissue samples, such as papillary muscles. To correct this problem, we have designed a tissue bath that virtually eliminates gas bubble interference. This design incorporates many desirable features of our High-Tech tissue baths. Utilizing the basic principles from a design by the eminent physiologist J.R. Blinks (J. Appl. Physiol. [1965] 20:755-7), the bath is a dual-chambered U-tube with a bridge connection midway between the two chambers. One chamber is used for aeration and has a removable aerating tube with a Teflon needle valve to permit fine adjustments to the gas flow. The tissue sample is placed in the other chamber. There is a circulating current generated by the rising gas bubbles during aeration. This design efficiently separates gas bubbles from the tissue chamber, yet it allows the oxygen-enriched perfusate to circulate through both chambers. Stimulating electrodes or other apparatus may be inserted into either or both chambers. Superfusate passes through the pre-warming coil built into the water-jacket and emerges at the desired temperature. An overflow outlet has been added to permit continuous or automated bath washing. Radnoti Quick Disconnect fittings are used to connect the water jacket to a temperature controlled re-circulating water bath. The tissue bath is drained from the bottom through a removable Luer lock stopcock. The tissue bath will serve admirably in cases where the researcher must resolve extremely small tissue force measurements or in cases where direct aeration would cause problems. Other potential uses would be side-by-side comparisons of tissues in the same bath, such as vessel rings with and without endothelium, etc.