sentence: Quantification of total LCB content by addition of an internal standard ( d20 :0 ) prior to hydrolysis of a pre ‐ weighed amount of lyophilized tissue indicated that sbh protonemata contained approximately 2.4 ‐ fold more sphingolipid than WT ( 11.0 ± 1.64 nmol mg DW for sbh vs. 4.60 ± 0.60 nmol mg DW for WT ) , which corresponded to a 200 ‐ fold increase in total d18 :0 content .