Purification of ricinosomes on a 44–65% sucrose gradient and Western
blot analysis (fraction 1, upper part, and fraction 24, lower part, of
the gradient) by using antibodies against the ricinosome marker enzyme
CysEP, against the ER-resident BiP (Hsp70) and against marker enzymes
for glyoxysomes (gMDH) and mitochondria (mMDH). Fractions 22–24
contain ricinosomes with no contamination by mitochondria or
glyoxysomes. Anti-BiP antibodies give a strong signal with the ER in
the upper part of the gradient, and a smaller peak in fractions 22–24
containing ricinosomes.