
Diff-Quik is a commercial
Romanowsky stain
Romanowsky staining, also known as Romanowsky–Giemsa staining, is a prototypical staining (biology), staining technique that was the forerunner of several distinct but similar stains widely used in hematology (the study of blood) and cytopathol ...
variant used to rapidly stain and differentiate a variety of
pathology
Pathology is the study of the causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in ...
specimens. It is most frequently used for
blood films and
cytopathological
Cytopathology (from Ancient Greek, Greek , ''kytos'', "a hollow"; , ''pathos'', "fate, harm"; and , ''-logy, -logia'') is a branch of pathology that studies and diagnoses diseases on the cellular level. The discipline was founded by George Nico ...
smears, including
fine needle aspirates.
[ ] The Diff-Quik procedure is based on a modification of the
Wright-Giemsa stain
Wright's stain is a hematologic stain that facilitates the differentiation of blood cell types. It is classically a mixture of eosin (red) and methylene blue dyes. It is used primarily to stain peripheral blood smears, urine samples, and bone ma ...
pioneered by Harleco in the 1970s,
and has advantages over the routine Wright-Giemsa staining technique in that it reduces the 4-minute process into a much shorter operation and allows for selective increased eosinophilic or basophilic staining depending upon the time the smear is left in the staining solutions.
There are generic brands of such stain,
and the trade name is sometimes used loosely to refer to any such stain (much as "Coke" or "Band-Aid" are sometimes used imprecisely).
Usage
Diff-Quik may be utilized on material which is ''air-dried'' prior to alcohol
fixation rather than immersed immediately (i.e. "wet-fixed"), although immediate alcohol fixation results in improved microscopic detail.
The primary use of Romanowsky-type stains in cytopathology is for
cytoplasmic detail, while
Papanicolaou stain
Papanicolaou stain (also Papanicolaou's stain and Pap stain) is a multichromatic (multicolored) cytological staining technique developed by George Papanicolaou in 1942. The Papanicolaou stain is one of the most widely used stains in cytology, whe ...
is used for nuclear detail. Diff-Quik stain highlights cytoplasmic elements such as
mucins
Mucins () are a family of high molecular weight, heavily glycosylated proteins ( glycoconjugates) produced by epithelial tissues in most animals. Mucins' key characteristic is their ability to form gels; therefore they are a key component in mo ...
, fat droplets and neurosecretory granules. Extracellular substances, such as free mucin, colloid, and
ground substance Ground substance is an amorphous gel-like substance in the extracellular space that contains all components of the extracellular matrix (ECM) except for fibrous materials such as collagen and elastin. Ground substance is active in the development, ...
, are also easily stained, and appear
metachromatic Metachromasia (var. metachromasy) is a characteristical change in the color of staining carried out in biological tissues, exhibited by certain dyes when they bind to particular substances present in these tissues, called chromotropes. For example ...
. Major applications include
blood smear
A blood smear, peripheral blood smear or blood film is a thin layer of blood smeared on a glass microscope slide and then stained in such a way as to allow the various blood cells to be examined microscopically. Blood smears are examined in the ...
s,
bone marrow
Bone marrow is a semi-solid tissue found within the spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It is composed of hematopoieti ...
aspirates,
semen analysis
A semen analysis (plural: semen analyses), also called seminogram or spermiogram, evaluates certain characteristics of a male's semen and the sperm contained therein. It is done to help evaluate male fertility, whether for those seeking pregnanc ...
and cytology of various
body fluid
Body fluids, bodily fluids, or biofluids, sometimes body liquids, are liquids within the human body. In lean healthy adult men, the total body water is about 60% (60–67%) of the total body weight; it is usually slightly lower in women (52-55%) ...
s including
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Cellular ...
and
cerebrospinal fluid
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.
CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...
.
Microbiologic agents, such as bacteria and fungi, also appear more easily in Diff-Quik.
This is useful for the detection of for example ''
Helicobacter pylori
''Helicobacter pylori'', previously known as ''Campylobacter pylori'', is a gram-negative, microaerophilic, spiral (helical) bacterium usually found in the stomach. Its helical shape (from which the genus name, helicobacter, derives) is th ...
'' from gastric and pyloric specimens.
Due to its short staining time, Diff-Quik stain is often used for initial screening of cytopathology specimens. This staining technique allows the
cytotechnologist or
pathologist
Pathology is the study of the causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in t ...
to quickly assess the adequacy of the specimen, identify possible
neoplastic
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
or inflammatory changes, and decide whether or not additional staining is required.
Components
The Diff-Quik stain consists of 3 solutions:
*Diff-Quik fixative reagent
**
Triarylmethane dye
Triarylmethane dyes are synthetic organic compounds containing triphenylmethane backbones. As dyes, these compounds are intensely colored. They are produced industrially as dyes.
Families
Triarylmethane dyes can be grouped into families accordin ...
**
Methanol
*Diff-Quik solution I (
eosinophilic
Eosinophilic (Greek suffix -phil-, meaning ''loves eosin'') is the staining of tissues, cells, or organelles after they have been washed with eosin, a dye.
Eosin is an acidic dye for staining cell cytoplasm, collagen, and muscle fibers. ''E ...
)
**
Xanthene dye (
Eosin Y
Eosin Y, also called C.I. 45380 or C.I. Acid Red 87, is a member of the triarylmethane dyes. It is produced from fluorescein by bromination.
Use
Eosin Y is commonly used as the red dye in red inks.
It is commonly used in histology, most notab ...
)
**
pH buffer
A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is ...
*Diff-Quik solution II (
basophilic
Basophilic is a technical term used by pathologists. It describes the appearance of cells, tissues and cellular structures as seen through the microscope after a histological section has been stained with a basic dye. The most common such dye i ...
thiazine dyes)
**
Methylene blue
Methylthioninium chloride, commonly called methylene blue, is a salt used as a dye and as a medication. Methylene blue is a thiazine dye. As a medication, it is mainly used to treat methemoglobinemia by converting the ferric iron in hemoglob ...
**
Azure A
Azure A is an organic compound with the chemical formula C14H14ClN3S. It is a light blue to dark blue dye
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments ...
**pH buffer
Results
Alternatives
*
Wright Giemsa stain
*
Papanicolaou stain
Papanicolaou stain (also Papanicolaou's stain and Pap stain) is a multichromatic (multicolored) cytological staining technique developed by George Papanicolaou in 1942. The Papanicolaou stain is one of the most widely used stains in cytology, whe ...
References
{{Romanowsky stains
Staining
Histopathology
Hematopathology
Cytopathology
Romanowsky stains