The history of the development of DNA blotting is described in this chapter. DNA blotting, involving the transfer of electrophoretically separated DNA fragments to a membrane support through capillary action, is also known as Southern blotting. This procedure enables the detection of a specific DNA sequence by hybridization with probes. The term Southern blotting led to a "geographic" naming tradition, with RNA blotting bearing the name Northern blotting and protein transfer to membranes becoming known as Western blotting.

At the suggestion of Cambridge University Press – after my manuscript was completed – I commissioned five short commentaries by distinguished molecular biologists who had read my biography. These complement the Foreword by Sir Edwin Southern.

Fred Sanger (FS) and I (GB) are seated in a recording studio at Imperial College, London. This is a slightly edited transcript of the continuing interview.

Biography is perhaps one of the most difficult of all historical and literary ventures, because it involves not only the compilation of material and its understanding, but also an attempt, which can never be wholly satisfactory, to enter into the soul of the subject and to create an honest account of life as well as to present a portrait.

Fred Sanger (FS) and I (GB) are seated in a recording studio at Imperial College, London. This is a slightly edited transcript of the final interview.

This review provides a perspective on the initial development of microarray technologies by two independent groups in the late 1980s. © 2013 by The International Union of Biochemistry and Molecular Biology, 42(2):106–113, 2014.

The rational design of novel triarylmethyl (trityl)-based mass tags (MT) for mass-spectrometric (MS) applications is described. We propose a "pKR+ rule" to correlate the stability of trityl carbocations with their MS performance: trityls with higher pKR+ values ionise and desorb better. Trityl blocks were synthesised that have high pKR+ values and are stable in conditions of MS analysis; these MTs can be ionised by matrix as well as irradiation with a 337 nm nitrogen laser. 13C-Labelled tags were prepared for MS quantitation applications. Moreover, the tags were equipped with a variety of functional groups allowing conjugation with different functionalities within (bio)molecules to enhance the MS characteristics of the latter. The MS behaviour of model polycationic trityl compounds with and without the matrix was studied to reveal that poly-trityl clusters are always singly charged under the (MA)LDI-TOF conditions. Several peptide-trityl conjugates were prepared and comparisons revealed a beneficial effect of trityl tags on the conjugate detection in MS. Trityl compounds containing para-methoxy- and dimethylamine groups, as well as a xanthene fragment, showed considerable enhancement in MS detection of model peptides; thus they are promising tools for proteomic applications. Dimethoxytrityl derivatives allow one to distinguish between Arg- and Lys-containing peptides. Maleimido trityl derivatives are suitable for the efficient derivatisation of thiol-containing peptides in pyridine.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS) is becoming a popular tool for imaging histological sections. Currently, this technology is used to image naturally occurring molecules. Here we report a novel development for multiplex imaging of candidate proteins. Rather than detecting whatever molecules happen to be present and above the detection threshold in the desorption pixel, we attach photocleavable mass tags to antibodies to target proteins. 'Staining' of histological sections is carried out similarly to common immunohistochemical procedures with chemiluminescent or fluorescent detection using all antibodies of a multiplex simultaneously. Mass tags with discrete masses are released from their respective antibodies by a laser pulse at 355 nm without added matrix. After scanning, mass spectrometry images are created for the mass of each tag. In contrast to fluorescent tags, mass tags do not exhibit mutual quenching. Sections of healthy human pancreatic tissue were imaged to visualize synaptophysin in neuroendocrine cells, and sections from human lymph node and liver invaded by metastatic melanoma to localize the cancer markers PS100 and HMB45 simultaneously. All these proteins are below the detection threshold of direct MALDI-MS imaging. This method is termed TAMSIM for TArgeted multiplex Mass Spectrometry IMaging.

A new method suitable for single nucleotide polymorphism detection and other applications based on oligonucleotide probe extension has been developed. The method is based on mass spectrometry and utilizes a single surface for affinity purification of extended probes and matrix-independent desorption/ionization of the cleavable labels. A new family of sulfur-linked laser-cleavable trityl labels with vastly improved flying abilities is implemented in this study. Corresponding reagents compatible with automated oligonucleotide synthesis are presented. Utility of this method for SNP genotyping is demonstrated.