A" direct-coloring" thiocholine method for cholinesterases

MJ KARNOVSKY, L Roots - Journal of Histochemistry & …, 1964 - journals.sagepub.com
MJ KARNOVSKY, L Roots
Journal of Histochemistry & Cytochemistry, 1964journals.sagepub.com
Ins thue exheussivelv ussed Koelle; onsd Fniederuwald histociueuusbcal nuetisod Ion
cisolinsestersose, amid its several ns (odificat ions (see Pearse, Histocheun istry, 2moded.,
p. 478, Little, Brown & Co., Bostons, 1960), thse tiuiociso) biose ester used as substrate is
hydroiysed by cholimsestenosse, oond the liberated hhiocisohinue is captured h)\Cu icns,
pnecipitatirug sos colorless copper thiocisolbuse. The latter is con-vented to broot-nisis CuS
by treatiuseust ot-iths yellow aissosuonununsu sulfide. Voonious steps irs thse nusethod …
Ins thue exheussivelv ussed Koelle; onsd Fniederuwald histociueuusbcal nuetisod Ion cisolinsestersose, amid its several ns (odificat ions (see Pearse, Histocheun istry, 2moded., p. 478, Little, Brown & Co., Bostons, 1960), thse tiuiociso) biose ester used as substrate is hydroiysed by cholimsestenosse, oond the liberated hhiocisohinue is captured h)\Cu icns, pnecipitatirug sos colorless copper thiocisolbuse. The latter is con-vented to broot-nisis CuS by treatiuseust ot-iths yellow aissosuonununsu sulfide. Voonious steps irs thse nusethod hsove-bee-mu criticized(Ion discussion see Pearse, ibid.). Lsorge useedle-like(‘rystals(occur l) articU-bsonly sot sites oof isigh activity, at higher pH levels, oomsd wihis cvenlcomsg incusbatioru. Under somuse cmcuuuushsonuces, the crystals coons soppanently increase ins size-by nsonu-euszvussat be-soccnetions.(Mabnsgren sonod Syivomu, J. Histocheun., 3: 441, 1955). Tise so (lvsonstages ccl thie presemutly described nssethsood sore: colour is prooduced directly at the site of eoozyusuatic activity, facilitating estinsation of h. hue ooptinuuius imscusi) soti000s tinse; the l) necipitate is finselv grssusuulan, so) lhooot, eveos witis prolonged incusbosoh booms, needle-like deposits are not ob) served; instemuse cnol (on sond contnsost coon conseqtiently be l) rodltlce-ib, somuch sites 0) 1 low activity ussoone easily detected.
TIse bsosis ol hbue issethod is that hisiochcdimse- is l) elieved Its recluse-c ferricysonside to lerrocyoonide prefenenstisolly. The lootter coomiuhimues with Cu#{176} iomus to lonuss the iossolusb) le copper femnocyoonide (Hsotcheht’s l3rcowns). Tise Cti ions in the ussedium sore cocosuplexetl wit Is cit nsote too prevent fonisuation oof copper fennicysonside.
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