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Fixation Reagents: Perfect Protection

Merck:/Freestyle/LE-Lab-Essentials/Microscopy/LE-Fixation-120x95-08262013.jpgIn microscopy, fixation is a prerequisite to further processing of clinical material, such as blood smears, histological tissue or gynecological samples. During fixation, all potentially infectious material is deactivated, cellular activity is stopped, and processes such as autolysis, decomposition and putrefaction are prevented. However, the structure and condition of the sample is preserved as much as possible. The choice of fixation reagent (fixative) depends on the diagnostic objectives, type and size of sample material, subsequent embedding technique, and staining method. 

MilliporeSigma offers an extensive range of fixatives to address all of these factors. Thanks to their excellent quality and batch-to-batch consistency, our reagents guarantee reliable and reproducible results. As with all of our microscopy products, our fixation reagents are CE -registered certified IVDs. Hence, they are safe to use for clinical diagnostics and support laboratory accreditation and audits.

M-Fix™ Spray Fixative

Whether for the classical or modified Papanicolaou staining technique, it is important that smears are fixed immediately while cells are still moist. For optimum protection against cell dehydration, MilliporeSigma offers the M-Fix™ spray fixative. The fixing reagent can be sprayed quickly and easily onto moist cell smears to build up a thin, even layer. This fixes the smear, while preventing the loss of moisture.

Features and Benefits

  • Optimum protection against cell dehydration
  • Retention of staining properties
  • Uniform coverage of cell smears
  • Quick, simple procedure

Learn more about our latest Universal Reagents products for microscopy by watching the video about M-Fix™

Fixation with Formaldehyde Solutions


Formaldehyde is one of the most common and effective fixatives used in histology. A 4 % solution of formaldehyde is equivalent to a 10 % solution of formalin. To prevent polymerization of the solution, approximately 10 –15 % methyl alcohol is added. Further stability is achieved by buffering the solution at about pH 6.9. This not only protects the user from the infectious potential of the sample material, but also preserves the tissue structures. Like this, a reliable processing of patients' samples for flawless histology staining, molecular pathology and IHC can be ensured.

Features and Benefits:

  • Easy and established fixation of histological samples 
  • 4% Formaldehyde equals 10% Formalin
  • Excellent protection from infectious potential of the samples 
  • Preservation of tissue structures
  • Buffered Formaldehyde solutions
  • 3 year stability at room temperature
  • IVD registered and CE certified

Product Range

An extensive selection of fixatives for microscopy, including acetic acid, acetone, ethanol, formaldehyde solution, glutardialdehyde solution and methanol, as well as fixative sprays such as M-Fix™.

All Fixation Reagents

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