In memoriam: Frederick Sanger

250px-Frederick_Sanger2Frederick Sanger, the only Briton to have won two Nobel prizes, has died. He worked in biochemistry, studying DNA and proteins. His first Nobel prize was awarded for being the first to sequence a protein, insulin. At the time, it required years of work to do so.  He found that it was made up of two peptide chains: all proteins are one or more peptide chains. He spent nearly ten years removing one amino acid at a time from the end of the protein and identifying it, then going on to the next.

Winning the prize enabled him to afford better facilities and gather bright students around him. His second prize was for an ingenious and efficient way of discovering the sequence of nucleotide bases in a molecule of DNA or RNA. The linking of base pairs gives the molecule its ladder structure. The Sanger method cuts the molecules at different places, sorts them by weight (and therefore length) and identifies the base on the end using fluorescent dyes of different colours. According to Wikipedia, he used the method sequence human mitochondrial DNA (16,569 base pairs) and bacteriophage λ (48,502 base pairs). His method was used to sequence the human genome and many others.

His work allowed us to understand the genetic basis of mutations and diseases and was important for the development of better vaccines. Frederick Sanger was also honoured with the Order of Merit for distinguished service in science as well as several other awards.

The Telegraph has quite a nice obituary: Frederick Sanger.

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Signal boost: more about squalenes

I put this into a comment but it deserves a wider readership.

squalene_01

Squalene is found in foods and your body makes it and uses it on the pathway to making cholesterol, which is a precursor to vital hormones. Your own blood contains sqalene. It is sold as a food supplement in the form of shark’s liver oil. Traces found in vaccines where it is not added appear to come from the oils left by fingerprints on laboratory glassware. The amounts found are far less than the concentration already in human blood.

The anthrax vaccine given to U.S. soldiers used aluminum hydroxide as an adjuvant. The purpose of an adjuvant is to boost immune response and allow us to use less of the antigen (disease substance that we want to become immune to). The U.S. doesn’t use squalene as an adjuvant in any vaccine. See this Q&A paper from the U.S. Food & Drug Administration (Portable Document Format file).

New views of Saturn!

Phil Plait has pictures and explanations of a large-scale image of Saturn taken by Cassini, along with a link to the full-size version: Saturn: incredible mosaic of the ringed wonder.

the planet Saturn, with its rings, glowing slightly. Shadows of rings appear on the planet

Saturn occluding the Sun

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