when human fibroblasts are incubated for 2-5 min with 20 microm [ 35s ] cystine in krebs-ringer phosphate solution at ph 7.4 , a minimum of 50-60 % of the total radioactivity taken up by the cells is found sequestered into the lysosomal compartment in the form of cysteine .
C0016030
fibroblasts
C0007634
cells