Microsomes are artificially formed vesicles derived from:
Cell fractionation pioneered by Claude and Palade showed that mechanical homogenization shears endoplasmic reticulum tubular network into small vesicles that reseal spontaneously due to energetically unfavorable exposed hydrophobic edges. These vesicles called microsomes sediment at one hundred thousand times g, one hundred to three hundred nanometers diameter retaining orientation original membrane. Rough microsomes bear ribosomes and contain Sec61 translocon, oligosaccharyltransferase, BiP, permitting in vitro translation translocation assays that defined signal peptide cleavage and core gly
Ref: Palade Science 1975; microsomes ER fragments 100k g in vitro translation translocation Nobel work.
