A comparison of the growth of sarcoma and carcinoma cultivated in vitro. 1

We have used in this study a rat sarcoma, a mouse sarcoma and a mouse carcinoma, transplantable tumors of a high degree of virulence. The technique has been practically the same as that employed by Burrows in the cultivation of the tissues of chick embryos and subsequently by Carrel and Burrows in the growth of various mammalian tissues; that is, plasma was obtained by centrifugalizing fresh blood under conditions that prevent coagulation and allowing it to clot in hanging drops which contained small pieces of tumor tissue. These preparations were incubated at 37° C. We have found that rat sarcoma grows in both rat plasma and mouse plasma, and that this is also true of mouse sarcoma. The growth in both instances, however, seems to be more vigorous and of longer duration when homologous plasma is used.

For the character of the growth in vitro, a description of the growth of mouse sarcoma in mouse plasma will suffice. The edges of a piece of sarcoma embedded in plasma are at first fairly uniform in thickness and the piece of tissue is dense and opaque. After twelve hours of incubation at 37° numerous elongated cells project from all sides of the tissue and these wander out into the surrounding plasma by amœboid motion. The throwing out of pseudopods and the associated streaming of the protoplasm can be seen quite beautifully under the microscope. As the cells wander from the original piece of tissue, it becomes less dense and we have observed very frequently the reduction of the original piece of sarcoma tissue to only a fraction of its initial size.