The use of modified Cunningham chambers for the enumeration of H rosettes, E rosettes, and lymphocyte-tumour cell conjugates.

In this paper, we have described the use of a slide-coverslip Cunningham chamber which is ideal for counting delicate rosettes and lymphocyte-tumour cell conjugates. The ease of construction, facility of use, and economy of cost in comparison with hemocytometers make the use of these chambers the method of choice for rosette counts in general. In contrast to standard double-slide Cunningham chambers, the design of these rosette chambers is such that they can be used with ordinary light microscope objectives (including oil immersion), they can be more easily loaded without trapping air bubbles, and they can be sealed without tilting the slide. As an example of one potential application of these chambers to tumour immunology, data have been presented showing the high proportion of lymphocyte-tumour cell conjugates which can be formed by human peripheral blood cells. The ability of any particular tumour cell to form conjugates did not necessarily reflect the susceptibility of that cell type to natural killer (NK) cell-mediated lysis, nor was there any evidence that E rosette-forming cells preferentially formed conjugate in comparison to non E rosette-forming cells.