A procedure is presented for the purification of specific mRNAs, which exploits the ability of antibodies prepared against a native protein to bind to the nascent polypeptide on the polysome. Rather than precipitating these soluble antibody-polysome complexes with anti-antibody, which can lead to nonspecific trapping of polysomes, we have linked the anti-antibody to an insoluble matrix. Thus, the antibody-polysome complex binds to the anti-antibody support and nonspecific polysomes can easily be removed by several washes. We have found para-aminobenzyl cellulose (PAB cellulose), to be a suitable matrix for this purpose. This support can bind large quantities of anti-antibody and it displayed no detectable nonspecific affinity for polysomes or RNA. Using this procedure, we have obtained an apparently homogeneous preparation of ovalbumin mRNA.

SUMMARY Four cases of tumours arising from Moll's glands, two benign mixed tumours of the skin (chondroid syringomas) and two adenocarcinomas, are reported. Three of the patients were over 40 years old. Contrary to the common assumption that malignant Moll's gland tumours are of low-grade malignancy, the two adenocarcinomas described here were highly malignant. Despite vigorous treatment, including orbital exenteration and lymph node resection, one was rapidly fatal and the other recurred with extensive involvement of the paranasal sinuses.