A simple technique for the determination of kappa and lambda immunoglobulin light chain expression by B cells in whole blood.

This article describes the development of a simple technique by which the numbers of surface immunoglobulin expressing cells can be analysed by dual fluorescence flow cytometry in samples of whole blood. We have compared the results obtained using this procedure with those obtained using samples prepared by traditional density gradient centrifugation, and demonstrate an excellent correlation between the two techniques. The method is applicable both to blood samples from normal individuals and from patients with B cell malignancies such as B-CLL and B-NHL. We have also confirmed previous findings that density gradient centrifugation may preferentially deplete certain lymphocyte subsets. This technique offers the following advantages: (i) it is rapid, (ii) it is accurate, (iii) it is reliable, (iv) it is useful in cases of lymphopenia, and (v) it requires only a small volume of blood. It is likely to be applicable to other situations in which the presence of serum factors interfere with antibody staining in whole blood.