The two papers that I read this past week could definitely be considered ancestral of sorts to the Fiddyment paper whose procedure I’ll be using this summer. They were a great insight into the research that led up to the eZooMS technique, and each involved the collagen mass fingerprinting of animal bones.
While it is possible to make an educated guess as to which animal a bone belonged to based on morphological characteristics alone, when the animal died very young or when the sample is highly fragmented then there is great potential for mistake. Ancient DNA sequencing is another method which could differentiate between species, but ancient DNA is quite unstable and difficult to store for analysis. Buckley et al propose that collagen analysis is cheaper, easier, and more practical.
The methods that they used were very clearly what Fiddyment et al based their technique upon before making alterations: basically, the collagen is gelatinized/denatured, digested into peptide chains with trypsin, extracted with a C18 solid phase method, and then assessed using MALDI-TOF. In this case, however, the collagen is extracted destructively.
One of the papers applied their peptide mass fingerprinting method to everything from sperm whale to pygmy hippo to hyena bones and also assessed whether their technique applied to – and give me a moment here – INDUSTRIALLY HEAT-RENDERED MEAT AND BONE MEAL(!!)(?)(!). Hint: it definitely can be, which is both a) awesome and b) applicable to the gelatin industry. I don’t know, I thought that was great. But anyway, the results that they obtained here contributed to the online database that we’ll be using to compare our MALDI spectra to.
The other paper used the same techniques but was centered on the more tricky distinctions that must be made between sheep and goat MS spectra. Not only are sheep and goat bones very similar morphologically, but their spectra are also pretty close. Buckley et al outlined a simple way to tell them apart, however, and it’s by looking at the location of just one peak and whether it appears at ~3033 or ~3093 m/z. Very cool and very practical for our future use!
Next week: collagen chemistry.