50 years ago

A new and rapid technique of characterizing the chemical properties of a protein in considerable detail has been devised; by its application a specific difference is found in the sequence of amino-acid residues of normal and sickle-cell haemoglobin. This difference appears to be confined to one small section of the polypeptide chains... The action of trypsin on proteins is at present the most reliable way of splitting a peptide chain at specific peptide bonds...Small differences in the two proteins will result in small changes in one or more of [the resulting] peptides. These should be detectable when the mixture is examined by a two-dimensional combination of paper electrophoresis and paper chromatography. It was decided to call the resulting chromatogram the 'finger print' of the protein.

V. M. Ingram

From Nature 13 October 1956.

100 years ago

In my address at York I urged biometricians to make sure that the problems they seek to elucidate are sound from a biological point of view. When asked by Prof. Pearson for an instance of failure in this respect I gave him, while away on my holiday, and in a private letter, Dr. Pearl's paper. He has now seen fit, although I twice asked him to wait for a full answer until my return to Cambridge, to challenge me to show in the pages of NATURE how my advice was applicable to that paper. I must leave your readers to judge how far I have succeeded in so doing.

The task has been far from an agreeable one. I should never have thought of singling Dr. Pearl's paper out for public criticism in this manner had I not been challenged to do so. I can only say that if he feels himself aggrieved at the result, he can be in no doubt whom he has to thank.

J. J. Lister

From Nature 11 October 1906.