Fig. 3.

Optimization of hydroxylamine (HA) digestion conditions. Hydroxylamine digest optimization was tested over several rounds of sample processing. Results were aggregated by comparing each digestion method with the reference sample run in parallel with treatment conditions (all n = 3). Results are presented and colored as fold change in relation to reference. Reference HA digest was performed in 1M HA-HCl pH 9.0 at 37 °C for 4 h with reduction and alkylation prior to digestion. A detailed reference protocol can be found in the Experimental Procedures section. In the final column, GAG refers to the addition of GAG-digesting enzymes. Samples with fold change <1 are shown as negative reciprocal values.