05-01004F – Formalin 10% neutral buffered ( 5L /1 tank)
Packaging Primary container: neutral container in PP. Blue screw cap in PE, watertight.
Secondary container: closed carton box, neutral colour.
Wear, water, alcohol and solvents resistant PVC label. Scratchproof ink resistant to water
Expected aim Product for the preparation of cyto-histological samples for optical microscopy.
Specifications pH 7,0 -7,2 ± 0,2
Buffer molarity 0.05 M
Application Universal fixative for histological specimens.
Principle The 10% formalin neutral buffered (equivalent to an aqueous solution of 4% formaldehyde)
is the fixative most commonly used in the histopathological routine. The interaction
between formaldehyde and functional groups present in tissue macromolecules (proteins
and nucleic acids) occurs according to the following scheme:
formation of methylene glycol: the molecule of formaldehyde in water gives rise to the
CH2O + H2O = CH2(OH)2
The methylene glycol is the chemical species that interacts primarily with the functional
groups present in the side chains of the proteins and with acids stabilizing the nuclear
secondarily formaldehyde form crosslinks between the free amino groups present in the
side chains of amino acids.
Fixation technique 1) 1) Volume ratio specimen/ fixative 1 : 50
2) Specimen thickness 1 cm max
3) Fixation time at room temperature: for specimens up to 5 mm 5 hours, for greater
thickness 1-2 days.