Tan C, Dunn S, Kent GN, Randall AG, Edmondston SJ, Singer KP (2002) The effect of formalin-fixation on collagen and elastin crosslinks in human spinal discs and ligamentum flavum. Journal of Musculoskeletal Research 6: 89-100

Abstract

Due to the restricted access to fresh un-preserved tissue samples, the effect of formalin-fixation on the distribution and extent of collagen and elastin crosslinks in the matrix of human spinal discs was evaluated. Five lumbar discs and ligamentum flavum samples were harvested from two fresh cadaveric spines after routine post-mortem procedures. Anular (n=76), nuclear (n=28) and liagmentum flavum (n=58) samples were selectively removed from the spine and divided into two halves. One half was stored in 10% buffered formalin and the other half was stored in a freezer at -20°C. Samples from each half were dried, hydrolysed and assayed for collagen and elastin crosslinks using HPLC. Subsequently, samples were assayed initially at weekly intervals until the 5th week, and thereafter at varied weekly intervals until the 30th week.

There were no significant differences in the collagen content and the extent of pyridinoline, deoxypyridinoline, isodesmosine and desmosine crosslinks between fresh and formalin-fixed disc and ligament samples. There were also no significant trends in the collagen content or extent of collagen and elastin crosslinks after 30 weeks of formalin fixation, compared with baseline data.

Formalin-fixation does not significantly alter the collagen content or the extent of non-reducible collagen [pyridinoline, deoxypyridinoline], and elastin [desmosine and isodesmosine] crosslinks.