Acronyms and Abbreviations

Abstract

n many fields today abbreviations and acronyms are common. They provide a useful tool for shortening long words or expression in order to save time and space. Some well-known general examples are DVD (digital versatile disc), UNICEF (United Nations International Children’s Emergency Fund), NASA (National Aeronautics and Space Administration), and UN (United Nations). Abbreviations are extensively used in the scientific and medical communities. It is common practice to use abbreviations for long names of many clinical diseases and procedures, and for scientific techniques that have to be repeated many times in medical or scientific papers, posters, and oral presentations. This can cause substantial communication difficulties for individuals who are not familiar with English abbreviations in their field. The example below is meaningless to individuals who are not familiar with the abbreviations used.

In many fields today abbreviations and acronyms are common. They provide a useful tool for shortening long words or expression in order to save time and space. Some well-known general examples are DVD (digital versatile disc), UNICEF (United Nations International Children’s Emergency Fund), NASA (National Aeronautics and Space Administration), and UN (United Nations). Abbreviations are extensively used in the scientific and medical communities. It is common practice to use abbreviations for long names of many clinical diseases and procedures, and for scientific techniques that have to be repeated many times in medical or scientific papers, posters, and oral presentations. This can cause substantial communication difficulties for individuals who are not familiar with English abbreviations in their field. The example below is meaningless to individuals who are not familiar with the abbreviations used.

For example,

IHC study of CNS tissue from MS subjects demonstrated loss of PLP-expressing OLs.

Many individuals, including native English speakers, do not know the difference between an acronym and an abbreviation. Acronyms and abbreviations are formed by combining the first letter or letters of several words. All acronyms are abbreviations, but not all abbreviations are acronyms. An acronym is a special type of abbreviation that can be pronounced as a single word (it can be said), while all other abbreviations are pronounced letter by letter (you say each letter individually or spell it out).

For example,

AIDS is an acronym for Acquired Immune Deficiency Syndrome because you say the abbreviation as a word (“aydz”); whereas HIV is an abbreviation for Human Immunodeficiency Virus (in this case you say each letter individually).

It can be extremely frustrating and time-consuming trying to find out what certain commonly used acronyms and abbreviations mean. Abbreviations that some consider universally known may be obscure to others. In addition, shortened forms used in one country may not be understood in another. In order to eliminate guesswork and prevent frustration, we have put together an alphabetized list of the most commonly used English acronyms and abbreviations in biomedical research. We feel that having a central reference list at your fingertips could be quite helpful for your scientific communications.

Abbreviation Rules and Style Conventions in English

Apply the following guidelines when using abbreviations:

• On the first occurrence of an abbreviation, spell out the full term, with the abbreviation in brackets. Thereafter the abbreviated form may be used by itself.

  For example,

  Oligodendrocytes (OLs) are the cells responsible for producing a fatty protein called myelin. Each OL can supply myelin for several axons and each axon can be supplied by several OLs.

• Abbreviations may be pluralized by adding an s to the end. Plurals of capitalized abbreviations should have no apostrophe because the apostrophe indicates possession. However, plurals of lowercase abbreviations have an apostrophe.

  Examples:

  PCRs (not PCR’s)

  BACs (not BAC’s)

  Drs. (not Dr’s)

  rbc’s (not rbcs)

  Exception 1: Plurals of some abbreviations, particularly in references, are not formed by merely adding an s.

  Examples:

  p for page and pp for pages (not ps or pgs)

  l for line and ll for lines (not ls)

  c for column and cc for columns (not cs)

  Exception 2: Singular and plural units of measure are abbreviated the same. An s is generally not added to the plurals.

  1 km and 5 km (not 5 kms)

  Exception 3: If the abbreviation contains a period (full stop), form the plural with an apostrophe and an s (’s). This is probably because it looks more awkward without apostrophes:

  For example,

  Ph.D.’s

  M.D.’s

  Exception 4: Plurals of single-letter abbreviations are formed by adding [’s].

  For example,

  X’s

• Abbreviations may be made possessive by adding ’s for singular possessive, and s’ for plural possessive.

  For example,

  EMBO’s homepage

• Articles are usually omitted when acronyms are used, being included only when terms or names are written out in full.

  Example:

  The United Nations International Children’s Emergency Fund is a voluntarily funded agency.

  UNICEF was created on December 11, 1946.

• The choice of an indefinite article (a or an) before letter-by-letter abbreviations depends on the pronunciation of the first letter of the abbreviation, not on the written representation of the first letter. If the abbreviation begins with a consonant sound, use a. If it begins with a vowel sound, use an.

  Examples:

  an mRNA molecule - although “m” is a consonant, we use the an article because the first sound we make is an “em” sound.

  an X-ray - this abbreviation begins with a consonant letter, but sounds like it starts with a vowel. The first sound we make is an “eks” sound.

There are several abbreviation styles used today. The only rule one should remember is to have a consistent style.

• Acronyms are generally presented in uppercase letters.

  Examples:

  AIDS, NATO, BBC, and SARS

  However, some acronyms are no longer capitalized. Examples are laser, radar and sonar.

• A period is sometimes written after an abbreviated word (there is no strict rule). The general modern trend is to omit periods from abbreviations (to avoid an appearance of clutter).

Organizations, countries, and units of measure are not generally followed by periods.

Examples:

EU (not E.U.)

UN (not U.N.)

IBM (not I.B.M.)

5 mg (not 5 mg.)

Periods are optional with degree titles (this is a matter of preference). However, in modern usage, periods are usually omitted.

Examples where both forms are acceptable:

PhD or Ph.D.

BSc or B.Sc.

MD or M.D.

• If a sentence ends with an abbreviation that requires a period, do not add another period.

  For example,

  The technician will be here at 4 p.m.

  not The technician will be here at 4 p.m.

• Abbreviations of chemicals from the periodic table always start with a capital letter; if there is a second letter, it is always lowercase.

  For example,

  N Nitrogen

  O Oxygen

  Na Sodium

  Zn Zinc

• Do not divide abbreviations, or a numerical value followed by a unit of measure, between lines on a page.

  ………………AIDS ………………10 mg

  not……………AI not………………10

  DS mg

Table 1.

List of abbreviations and Latin expressions used in scientific writing

Abbreviation	Expression	Translation
c. or ca.	Circa	About (in reference to approximate date or time)
c.f.	Con fero	Compare, consult
–	Et	And
et al.	Et alii	And others (in reference to people)
etc.	Et cetera	And so forth, and so on
et seq.	Et sequentes	And the following
e.g.	Exempli gratia	For example
Ibid.	Ibidem	The same place
i.e.	Id est	That is
l.c. or loc. cit.	Loco citato	At the place already cited
N.B.	Nota bene	Note well (to draw attention to something)
op. cit.	Opere citato	In the work cited
P.S.	Post scriptum	After writing (in reference to additions to a letter after the signature)
q.v.	Quod vide	Which see (in reference to a term/sentence to be looked up elsewhere
sc.	Scilicet	Namely, to wit
-	Sic	As such, thus, so, just as that
vs.	Versus	Against
Viz.	Videlicet	Namely, to wit

General Abbreviations and Acronyms Used in Biomedical Research

Abbreviations Definition

A

Adenine or alanine

aa

Amino acid or aminoacyl

Ab

Antibody

ABU

L-a-Aminobutyric acid

ABZ

2-Aminobenzoyl

AC

Accession number

ac

Acetyl

Ac

Actinium

Ac-CO A

Acetyl-coenzyme A

AChE

Acetylcholinesterase

Acm

Acetamidomethyl

ADH

Alcohol dehydrogenase

ADP

Adenosine diphosphate

AFC

7-Amino-4-trifloromethyl-coumaride

Ag

Antigen or silver

Aha

7-Aminoheptanoic acid

Al

Aluminum

Ala

Alanine

Am

Americium

AMP

Adenosine monophosphate

Amp

Ampicillin

an

Anisoyl

ANOVA

Analysis of variance

AP

Anteroposterior or action potential or alkaline phosphatase

APC

Antigen presenting cells

apoE

Apolipoprotein E

APP

Amyloid Precursor Protein

APS

Ammonium persulfate

Ar

Argon

Arg

Arginine

As

Arsenic

ASA

Acetyl salicylic acid

Asn

Asparagine

Asp

Aspartic acid

At

Astatine

ATP

Adenosine 5’- triphosphate

ATPase

Adenosine triphosphatase

Au

gold

B

B

Boron or bromouridine

Ba

Barium

BAC

Bacterial artifi cial chromosome

BAP

Bacterial alkaline phosphatase

BCIP

5-Bromo-4-chloro-3-indolyl phosphate

Be

Beryllium

bh

Benzhydryl

Bh

Bohrium

Bi

Bismuth

Bio-dNTP

Biotin-deoxynucleoside triphosphate

Bk

Berkelium

BLAST

Basic Local Alignment Search Tool

BME

Beta-mercaptoethanol

BMT

Bone marrow (or blood and marrow) transplant

Bp

Base pair

Br

Bromine

BrUrd

Bromouridine

BSA

Bovine serum albumin

bz

Benzoyl

bzy

Benzyl

C

C

Carbon or cytosine or cysteine

Ca

Calcium

CA

Casamino acids

CAT

Chloramphenicol acetyl

CD

Central domain

Cd

Cadmium

cDNA

Complementary deoxyribonucleic acid

Ce

Cerium

Cf

Californium

CFU

Colony-forming units

CIAP

Calf intestinal alkaline phosphatase

cl

Chloro

Cl

Chlorine

Cm

Curium

Co

Cobalt

Cr

Chromium

Cs

Cesium

CSF

Cerebrospinal fluid

CTP

Cytidine 5’-triphosphate

Cu

Copper

Cyd

Cytidine

Cys

Cysteine

D

D

Aspartic acid

dAMP

Deoxyadenosine monophosphate

dATP

Deoxyadenosine triphosphate

DAG

Diacylglycerol

Db

Dubnium

dCTP

Deoxycytidine triphosphate

ddATP

Dideoxycytidine triphosphate

ddCTP

Dideoxyadenosine triphosphate

ddGTP

Dideoxyguanosine triphosphate

ddNTP

Dideoxynucleoside triphosphate

DEAE

Diethylaminoethyl

DEPC

Diethyl Pyrocarbonate

dGTP

Deoxyguanosine triphosphate

DIDS

4,4’-di-isothiocyanato-2,2’-disulfostilbene

DIG

Digoxigenin

DIV

Days In Vitro

DMF

N,N-Dimethylformamide

DMS

Dimethylsulfi de

DMSO

Dimethyl sulfoxide

DMT

Dimethyltryptamine

DNA

Deoxyribonucleic acid

DNase

Deoxyribonuclease

dns

Dansyl

Dnp

2,4-Dinitrophenyl

dNTP

Deoxyribonucleotide triphosphate

DPI

Diphenylene iodonium

Dpr

2,3-Diaminopropionic acid

Ds

Darmstadtium

ds

Double stranded

DT

Diphtheria toxin

DTA

Diphtheria toxin A chain

DTE

Dithienylethene

DTT

Dithiothreitol

dTTP

Deoxythymidine triphosphate

dUTP

Deoxyuridine triphosphate

DV

Dorsoventral

Dy

Dysprosium

E

E

Glutamic acid

EDT

1,2-Ethanedithiol

EDTA

Ethylenediaminetetraacetic acid

EGTA

Ethylene glycol tetraacetic acid

ER

Endoplasmic reticulum

Er

Erbium

Es

Einsteinium

EtBr

Ethidium Bromide

EtOH

Ethanol

Eu

Europium

exo

Exonuclease

F

F

Fluorine or phenylalanine

fa

Formylaminoacyl

FBS

Fetal bovine serum

FCS

Fetal calf serum

Fe

Iron

FITC

Fluorescein isothiocyanate

Fm

Fermium

FOA

5-Fluoroacetic acid

Fr

Francium

FSH

Follicle-stimulating hormone

G

g

Gram

g

Gravitational force

G

Glycine

Ga

Gallium

Gd

Gadolinium

Ge

Germanium

GFP

Green Fluorescent Protein

Gln

Glutamine

Glu

Glutamic acid

Gly

Glycine

GM

Genetically Modified

GMO

Genetically Modified Organisms

GUS

Beta-D-glucuronidase

H

H

Hydrogen or histidine

Hb

Hemoglobin

HBSS

Hank’s Buffered Salt Solution

HCl

Hydrochloric acid

H&E

Hematoxylin and Eosin

He

Helium

HEPES

4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid)

Hf

Hafnium

Hg

Mercury

His

Histidine

HLA

Histocompatibility Leukocyte Antigen

hm

Hydroxymethyl

Ho

Holmium

HPRT

Hypoxanthine phosphoribosyltransferase

HRP

Horseradish peroxidase

Hs

Hassium

Hsp

Heat Shock Protein

HT

High temperature

hU

Dihydrouridine

humi.

Humidity

Hyl

Hydroxylysine

Hyp

Hypoxanthine

I

I

Iodine or isoleucine

Ig

Immunoglobulin

IgA

Immunoglobulin A (gamma A immunoglobulin)

IgD

Immunoglobulin D (gamma D immunoglobulin)

IgE

Immunoglobulin E (gamma E immunoglobulin)

IgG

Immunoglobulin G (gamma G immunoglobulin)

IgM

Immunoglobulin M (gamma M immunoglobulin)

IIe

Isoleucine

In

Indium

Ino

Inosine

IPP

Isopentenyl diphosphate

IPTG

Isopropyl-beta-D-thiogalactopyranoside

IR

Infrared

Ir

Iridium

k

K

Potassium or lysine

Kr

Krypton

L

L

Leucine

La

Lanthanum

LB

Luria-Bertani medium or Luria broth

Leu

Leucine

Li

Lithium

Lr

Lawrencium

LTA

Lipoteichoic Acid

Lu

Lutetium

Lys

Lysine

M

M

Methionine

mAb

Monoclonal antibodies

MCS

Multiple cloning site

Md

Mendelevium

MeOH

Methanol

Met

Methionine

Mg

Magnesium

MgCl

Magnesium chloride

MMLV

Moloney murine leukemia virus

mmt

Monomethoxytrityl

Mn

Manganese

Mo

Molybdenum

MOPS

4-Morpholinepropanesulfonic acid

mRNA

Messenger Ribonucleic Acid

Mt

Meitnerium

MTS

3-(4,5dimethylthiazol--yl)-5-(3- carboxymethozyphenyl-2-(4-sulfophenyl)-2H- tetrazolium

mtDNA

Mitochondrial DNA

N

N

asparagine or nitrogen

Na

Sodium

NaF

Sodium fl uoride

NAD

Nicotinamide adenine dinucleotide

NADH

Nicotinamide adenine dinucleotide (reduced form)

NADP

Nicotinamide adenine dinucleotide phosphate

NADPH

Nicotinamide adenine dinucleotide phosphate (reduced form)

Nb

Niobium

NBT

Nitroblue tetrazolium

Nd

Neodymium

Ne

Neon

Ni

Nickel

NMDA

N-methyl-D-aspartic acid

No

Nobelium

Np

Neptunium

nRNA

Nuclear RNA

NT

Nucleotides or nuclear transfer or null type

NTP

Nucleoside triphosphate

NZCYM

Casein hydrolysate casamino acids yeast extract magnesium medium

O

O

Oxygen or orotidine

OD

Optical Density

Oilgo(dT)

Oligodeoxythymidylic acid

OMP

Orotidine monophosphate

o/n

Over night

Ord

Orotidine

ORF

Open reading frame

Oro

Orotate

Os

Osmium

P

P

Phosphorus or praline

Pa

Protactinium

PAC

P1 artifi cial chromosome

Pb

Lead

PBMC

Peripheral blood mononuclear cells

PBS

Phosphate Buffer Saline

Pd

Palladium

PEI

Polyethylenimine

PEG

Polyethylene glycol

PFU

Plaque-forming units

Phe

Phenylalanine

PK

Protein kinase

PIPES

Piperazine-N,N’-bis(2-ethanesulfonic acid)

Pm

Promethium

PMSF

Phenylmethylsulfonyl fl uoride

PNK

Polynucleotide kinase

Po

Polonium

Poly(A)

Polyadenylic acid

Poly(A)+

Polyadenylated messenger Ribonucleic Acid

Poly(U)

Polyuridylic acid

Pr

Praseodymium

Pro

Proline

Pt

Platinum

PTX

Pertussis toxin

Pu

Plutonium

Puo

Purine nucleoside

Pur

Purine

PVC

Polyvinyl chloride

Pyd

Pyrimidine nucleoside

Pyr

Pyrimidine

Q

Q

Glutamine or ubiquinone (coenzyme Q)

R

R

Arginine

Ra

Radium

Rb

Rubidium

Re

Rhenium

Rf

Rutherfordium

Rg

Roentgenium

Rh

Rhodium

Rn

Radon

RNA

Ribonucleic acid

RNase

Ribonuclease

RNP

Ribonucleoprotein

RRM

RNA recognition motif

rRNA

Ribosomal ribonucleic acid

RT

Room temperature or reverse transcriptase

Ru

Ruthenium

Rxn

Reaction

S

S

Sulphur or serine

Sb

Antimony

Sc

Scandium

SDS

Sodium Dodecyl Sulfate

Se

Selenium

Ser

Serine

Sg

Seaborgium

Si

Silicon

Sm

Samarium

Sn

Tin

SR

Sarcoplasmic reticulum

Sr

Strontium

ss

Single stranded

SSC

Sodium citrate buffer

STR

Short tandem repeats

T

T

Threonine

Ta

Tantalum

TAE

Tris-acetate buffer

Taq

Thermus aquatic DNA polymerase

Tb

Terbium

TBE

Tris/Borate/EDTA buffer

TBS

Tris-Buffered Saline

TBST

Tris-Buffered Saline Tween-20

Tc

Technetium

TCA

Trichloroacetic acid

TdT

Terminal deoxynucleotidyl transferase

Te

Tellurium

TE

Tris/EDTA buffer

TEA

Triethanolamine

TEMED

N,N,N’,N’-Tetramethylethylenediamine

TES

N-Tris(hydroxymethyl)methyl-2- minoethanesulfonic acid

Tg

Transgenic

TGB

Tris/Glycine buffer

Th

Thorium

Thr

Threonine

Ti

Titanium

Tl

Thallium

Tm

Thulium

TP

Thymidine phosphorylase

TRIS

Tris-hydroxymethyl-aminomethanel

tRNA

Transfer RNA

Trp

Tryptophan

Tyr

Tyrosine

U

U

Uranium or uridine

UP

Uridine phosphorylase

Ura

Uracil

Urd

Uridine

UTP

Uridine triphosphate

UTR

Untranslated region

Uub

Ununbium

Uuh

Ununhexium

Uun

Ununnilium

Uuo

Ununoctium

Uup

Ununpentium

Uuq

Ununquadium

Uus

Ununseptium

Uut

Ununtrium

Uuu

Unununium

UV

Ultraviolet

V

V

Vanadium or valine

Val

Valine

W

W

Tungsten or tryptophan

WT

Wild-type

X

Xan

Xanthine

Xe

Xenon

X-Gal

5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside

X-Gluc

5-bromo-4-chloro-3-indolyl-beta-D-glucuronic acid

Y

Y

Yttrium or tyrosine

YAC

Yeast Artifi cial Chromosome

Yb

Ytterbium

YMG

Yeast and malt extract with glucose media

YPD

Yeast extract/peptone/dextrose bacterial media

YPG

Yeast extract/peptone/galactose bacterial media

YT

Yeast extract/tryptone bacterial media

Z

Zn

Zinc

Zr

Zirconium

Please note that amino acids are given three-letter and one-letter abbreviations (e.g. A or Ala for Alanine).

Methods and Techniques Used in Biomedical Research

CHEF

Contour-clamped homogeneous electric fi eld gel electrophoresis

CSGE

Conformation-sensitive gel electrophoresis

DFP

DNA fi nger printing

DGGE

Denaturing gradient gel electrophoresis

ELISA

Enzyme-linked immunosorbent assay

EMSA

Electrophoresis mobility shift assay

ENDO

Endodeoxyribonuclease assay

EXO

5’ and 3’ exodeoxyribonuclease assay

FACS

Fluorescence-activated cell sorting

FIGE

Field inversion gel electrophoresis

FISH

Fluorescent in situ hybridization

GC

Gas chromatography

HPLC

High performance liquid chromatography

HTRF

Homogeneous time-resolved fl uorescence assay

IEF

Isoelectric focusing

IHC

Immunohistochemistry

IP

Immunoprecipitation

ISH

In situ hybridization

LCR

Ligase chain reaction

MNR

Nuclear magnetic resonance

MS

Mass Spec

MZE

Multiphasic zone electrophoresis

NAAT

Nucleic acid amplifi cation technique

NB

Northern blot

PAGE

Polyacrylamide gel electrophoresis

PCR

Polymerase chain reaction

PFGE

Pulsed-fi eld gel electrophoresis

PRINS

Primed in situ labeling

qPCR

Quantitative PCR

RDA

Representational difference analysis

REMI

Restriction enzyme mediated integration

RFLP

Restriction fragment length polymorphism

RGE

Rotating gel electrophoresis

RPA

Ribonuclease protection assay

SB

Southern blot

SCGE

Single cell gel electrophoresis

SDA

Strand displacement amplifi cation

TAFE

Transverse alternating-fi eld electrophoresis

TAP

Tandem affi nity purifi cation

TGGE

Temperature gradient gel electrophoresis

TLC

Thin layer chromatography

WB

Western blot

Radioactive Isotopes

¹⁴C

Carbon-14

³H

Tritium-3

¹³¹I

Iodine-131

³²P

Phosphorus-32

³³P

Phosphorus-33

³⁵S

Sulfate-35

Cell Lines

3T3

Mouse embryo fibroblast cell line

9L

Rat glioma

A549

Human lung cancer cell line

B104

Rat neuroblastoma

BHK

Baby hamster kidney cells

B-LCL

B-lymphoblastoid cell line

C6

Rat glioma

CHO

Chinese hamster ovary

CLL

Carcinoma cell line

CMT

Canine mammary tumor

COS

(monkey kidney)

CV-C

African green monkey kidney cell line

EC

Embryonal carcinoma (human)

EJ

Human bladder cancer cell line

GH3

Rat pituitary tumor cell line

HaCaT

Human keratinocyte cell line

HEK

Human embryonic kidney

HeLa

Henrietta Lacks (human cervical cell line)

HL-60

Human leukemia cell line

MCF-7

Human breast cancer cell line

MDCK

Madin-Darby canine kidney

NS0

Mouse myeloma cell line

PC12

Chromaffin cell line (rat)

SCLC

Small cell lung cancer cell line

SPEV

Swine kidney cell line

SW480

Human colon cancer cell line

U87

Human glioblastoma-astrocytoma cell line

U343

Human astrocytoma cell line

Units of Measurement

Always abbreviate units when reporting numerical information. However, if you write the number out in full, you must spell out the unit of measurement. Always put a space between the number and the unit. When starting a sentence with a number and unit, both must be spelled out as words. Abbreviations for most units of measurement use small letters. The following abbreviations of units of measurement are frequently used in biomedical research.

A

Ampere

a

Area

A₂₆₀

Absorbance measured at 260 nm

Bq

Becquerel

C

Coulomb

^oC

Degree Celsius

cal

Calorie

Ci

Curie

cm

Centimeter

cpm

Counts per minute

d

Day

Da

Dalton

DIV

Days in vitro

dpm

Disintegrations per minute

F

Fahrenheit

g, gr

Gram (g is commonly used)

h

Hour

Hz

Hertz

J

Joule

k

Kilo (10³)

kb

Kilobases

kDa

Kilodalton

L

Liter

lb

Pounds

M

Molar

m

Meter

mA

Milliamps

Mb

Megabase

mg

Milligram

min

Minute

mL

Milliliter

mM

Millimolar

mmol

Millimole

mo

Month

mol

Mole

ms, msec

Milliseconds (ms is generally used)

mV

Millivolt

MW

Molecular weight

N

Newton

n

Nano or sample size

ng

Nanogram

nm

Nanometer

OD

Optical density

oz

Ounces

pH

Power of hydrogen

r

Revolution

rpm

Revolutions per minute

S

Svedberg units

s, sec

Seconds (s is generally used)

T_m

Melting temperature

U

Unit

μ

Micron

μM

Micromolar

μm

Micrometer

w, W

Watt (W is commonly used)

wk

Week

wt

Weight

w/v

Weight to volume

y

Year

V_max

Maximum velocity

v/v

Volume to volume