Unreliability of the microcomplement fixation method for Xg(a) typing of cultured fibroblasts

Evidence pointing to localization of the Xg locus on either the long or short arm of the X chromosome is conflicting. Whether the Xg locus is subject to X inactivation is also undecided. A report that Xg antigen could be detected on cultured fibroblasts or in hybridized cell lines by microcomplement fixation seemed to open new possibilities of studying these important problems. Indeed, Fellous et al., using the microcomplement fixation method, mapped the Xg locus to the short arm of the X chromosome by typing a human cell line involving a translocation, t(X;17)(p11;q20), of the X and chromosome 17. However, the authors were unable to duplicate the results of Fellous et al., whether they used their technique or their own.