II. Definitions
- Buccal Smear (or Sex Chromatin Test)
- Microscopy of cheek cell scraping
- Presence of barr bodies suggests 2 X-Chromosomes
- Barr Body
- Inactivated X-Chromosome in each cell of a female
- Seen as an intracellular dark spot on microscopy
III. History
- Barr Body first identified by Dr. Murray Barr in 1949
- Mary Lyon suggested etiology and named it Barr Body
IV. Physiology
- All cells in female, turn off 1 of 2 X-Chromosomes
- Occurs on day 16 of Embryonic development
- Each cell child inherits same inactivated X-Chromosome
V. Indications
- Replaced by karyotype for full chromosomal mapping
- Previously used to evaluate abnormal Sexual Development
VI. Procedure
- Gently scrape inside of cheek
- May use wooden Tongue blade or toothpick
- Spread sample onto slide into drop of saline
- Dry slide and stain with methylene blue 0.3%
VII. Interpretation
- Barr Body: Crumpled dark Chromosome seen in cell
- Suggests normal female karyotype 46XX
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Related Studies
| Definition (GO) | Chromatin that is part of a sex chromosome. [GOC:dos, ISBN:0198506732] |
| Definition (NCI) | The inactive, condensed X chromosome in a female somatic cell. |
| Definition (MSH) | In the interphase nucleus, a condensed mass of chromatin representing an inactivated X chromosome. Each X CHROMOSOME, in excess of one, forms sex chromatin (Barr body) in the mammalian nucleus. (from King & Stansfield, A Dictionary of Genetics, 4th ed) |
| Definition (GO) | A structure found in a female mammalian cell containing an unpaired X chromosome that has become densely heterochromatic, silenced and localized at the nuclear periphery. [GOC:hjd] |
| Concepts | Cell Component (T026) |
| MSH | D012728 |
| SnomedCT | 58348001 |
| LNC | LP18339-9, MTHU004078, LA11179-1 |
| English | Barr Bodies, Bodies, Barr, Chromatin, Sex, Chromatins, Sex, Sex Chromatin, Sex Chromatins, sex chromatin, Barr chromatin body, barr bodies, chromatin sex, barr body, Barr bodies, Barr body, Sex chromatin, Sex chromatin (substance), Barr Body |
| French | Corpuscules de Barr, Chromatine sexuelle |
| Swedish | Könskromatin |
| Czech | sexchromatin |
| Finnish | Barrin kappale |
| Russian | X-KHROMATIN, KHROMATIN POLOVOI, Y-KHROMATIN, BARRA TEL'TSA, POLOVOI KHROMATIN, X-ХРОМАТИН, Y-ХРОМАТИН, БАРРА ТЕЛЬЦА, ПОЛОВОЙ ХРОМАТИН, ХРОМАТИН ПОЛОВОЙ |
| Italian | Corpi di Barr, Cromatina sessuale |
| Latvian | Dzimumhromatīns |
| Polish | Ciałko Barra, Chromatyna płciowa |
| Japanese | クロマチン-性, 性クロマチン, バール小体, 性染色質, 染色質-性 |
| Norwegian | Kjønnskromatin, Barr-legemer, Barr-inklusjonslegemer |
| Spanish | cromatina sexual (sustancia), cromatina sexual, cuerpo de cromatina de Barr, Corpusculos de Barr, Cromatina Sexual |
| German | Chromatin, Geschlechts-, Geschlechtschromatin, Barr-Körperchen |
| Dutch | Barr-lichaampjes, Chromatine, sekse-, Seksechromatine |
| Portuguese | Corpos de Barr, Cromatina Sexual |
Ontology: buccal smear biopsy procedure (C0581714)
| Concepts | Diagnostic Procedure (T060) |
| SnomedCT | 31402005, 303995001 |
| LNC | LP7093-0, MTHU007944 |
| Italian | Striscio orale, Striscio buccale |
| Dutch | uitstrijkje wangslijmvlies, wangslijmvliesuitstrijkje |
| Japanese | 頬部スミア, ﾎﾎﾌﾞｽﾐｱ, ｷｮｳﾌﾞｽﾐｱ |
| Czech | Stěr z bukální sliznice |
| English | Smear buccal, buccal smears, buccal smear, Buccal smear for Barr bodies, Buccal smear for Barr bodies (procedure), Buccal smear, Buccal smear procedure, Buccal smear procedure (procedure), Buccal smear for Barr bodies (procedure) [Ambiguous], buccal smear biopsy procedure |
| Hungarian | Buccalis kenet |
| Spanish | extendido bucal para detección de corpúsculos de Barr, extendido bucal para detección de corpúsculos de Barr (procedimiento), frotis bucal, extendido bucal para detección de corpúsculos de Barr (concepto no activo), procedimiento de extendido de material del carrillo, procedimiento de extendido yugal (procedimiento), procedimiento de extendido yugal, procedimiento de frotis yugal, Frotis bucal |
| Portuguese | Esfregaço bucal |
| French | Frottis buccal |
| German | Mundabstrich |
