Colors and Additives 🧪

Which specimen type or laboratory department represents the primary use for red glass tubes that contain no additives?
Serum / chemistry and serology
Whole blood / hematology
Plasma / coagulation
Plasma / molecular diagnostics

What specific mechanism of action allows a red plastic/Hemogard tube to enhance serum specimen preparation?
Silica clot activator
Chelates and binds calcium ions
Inhibits thrombin formation
Inhibits the Mg-dependent enzyme enolase

Which specific form of anticoagulant is present within lavender glass tubes?
K3EDTA in liquid form
Spray-dried K2EDTA
Sodium citrate
Lithium heparin

Which tube option contains spray-dried K2EDTA and is designated for whole blood hematology testing?
Lavender (plastic)
Lavender (glass)
Light blue
Light green

Which tube contains spray-dried K2EDTA and is specifically designated for whole blood/blood bank and molecular diagnostics?
Pink
White
Royal blue
Light blue

Which tube features an additive composition consisting of EDTA and gel, and is utilized for plasma/molecular diagnostics?
White
Pink
Lavender (glass)
Black

Which anticoagulant is contained within light blue tubes used exclusively for plasma/coagulation testing?
Sodium citrate
K2EDTA
Lithium heparin
Sodium fluoride

What is the fundamental mechanism of action for the sodium citrate anticoagulant found inside light blue tubes?
Chelates (binds) calcium
Inhibits thrombin formation
Inhibits glycolysis
Activates the intrinsic pathway

Which tube contains a specialized mixture of thrombin and soybean trypsin, and is used for plasma/coagulation testing of fibrin degradation products?
Light blue with thrombin and soybean trypsin
Light blue with sodium citrate
Black with sodium citrate
Yellow with acid citrate dextrose

Which tube color contains sodium citrate and is explicitly designated for plasma/sedimentation rates (ESR) in hematology?
Black
Light blue
Pink
White

Which tube color features lithium heparin and gel as its additives and is designated for plasma/chemistry testing?
Light green/black
Green
Tan (glass)
Royal blue

What is the primary mechanism of action for the heparin anticoagulant found in green and light green tubes?
Inhibits thrombin formation
Chelates and binds calcium ions
Inhibits glycolysis by destroying enolase
Activates the extrinsic clotting cascade

Which tube features an additive composition of sodium heparin or lithium heparin and is used for plasma/chemistry?
Green
Light green/black
White
Lavender (plastic)

Which tube option contains sodium heparin or K2EDTA and is designated for plasma/chemistry/toxicology?
Royal blue
Green
Tan (plastic)
Light green/black

What specific dual mechanism of action occurs within a royal blue tube containing sodium heparin and K2EDTA?
Heparin inhibits thrombin formation while Na2EDTA binds calcium
Silica activates clots while sodium fluoride stops glycolysis
Sodium citrate chelates calcium while soybean trypsin inhibits thrombin
Sodium polyanetholesulfonate inhibits complement while heparin binds magnesium

Which tube color features a combination of sodium fluoride and potassium oxalate and is designated for plasma/glucose testing?
Gray
Tan (plastic)
Black
White

What is the explicit mechanism of action for the sodium fluoride component in gray top tubes?
Binds Mg++, thus inhibiting the Mg-dependent enzyme enolase
Chelates calcium ions to preserve platelets
Inhibits thrombin formation in cardiac panels
Activates fibrin degradation products

Which gray top tube option contains a sterile additive mixture containing sodium polyanetholesulfonate and is used for serum/microbiology culture?
Yellow
Gray
Tan (glass)
Pink

How does sodium polyanetholesulfonate (SPS) inside microbiology yellow tubes aid in bacterial recovery?
By inhibiting complement, phagocytes, and certain antibiotics
By chelating free calcium to prevent fibrin mesh formation
By providing essential nutrients that speed up bacterial metabolism
By cross-linking bacterial cell walls to prevent cell lysis

Which tube contains acid citrate dextrose (ACD) and is utilized for plasma/blood bank, HLA phenotyping, and paternity testing?
Yellow
White
Pink
Tan (plastic)

What is the explicit mechanism of action or function of the acid citrate dextrose (ACD) additive inside yellow blood bank tubes?
WBC preservative
Inhibits thrombin formation
Silica clot activator
Inhibits glycolysis

Which tube option features a glass structure, contains sodium heparin, and is used for plasma/lead testing?
Tan (glass)
Tan (plastic)
Royal blue
Green

Which tube option features a plastic structure, contains K2EDTA, and is used for plasma/lead testing?
Tan (plastic)
Tan (glass)
White
Lavender (glass)

Which tube contains thrombin, operates via a clot activator mechanism, and is utilized for serum/chemistry?
Yellow/gray and orange
Red/gray and gold
Red (plastic)
Red (glass)

Which tube contains a clot activator and a separation gel, operates via a silica clot activator mechanism, and is utilized for serum/chemistry?
Red/gray and gold
Yellow/gray and orange
Light green/black
White

What material is responsible for activating the intrinsic pathway inside an additive-free red glass tube?
Glass
Silica
Thrombin
Trypsin

How does the liquid form of K3EDTA inside a lavender glass tube impact red blood cells if the tube is underfilled?
Causes shrink RBCs
Causes swell RBCs
Causes immediate hemolysis
Causes macrocytic shifts

Which two specific red blood cell index values are affected if a lavender glass tube with liquid K3EDTA is underfilled?
Decreased MCV and decreased hematocrit
Increased MCV and increased MCHC
Decreased MCHC and increased hematocrit
Increased MCHC and decreased hematocrit

What clotting factor (CF IV) is directly bound by EDTA and sodium citrate to prevent the coagulation cascade?
Calcium
Prothrombin
Fibrinogen
Thrombin

What is the preferred or standard concentration of sodium citrate utilized in light blue tubes for routine coagulation testing?
3.2%
3.8%
4.1%
9:1

Why is a 3.8% sodium citrate concentration less preferred than a 3.2% concentration for routine coagulation testing?
Prone to over anticoagulation
Causes immediate fibrin polymer lysis
Inhibits the activity of factor VIII
Triggers artifactual platelet aggregation

What tube serves as the recommended alternative if a black top tube is completely unavailable for performing an ESR?
Lavender top
Light blue top
Green top
Gray top

Which group of anticoagulants or tubes is recognized as having the least chemical interferences, making them optimal for specialized chemistry assays?
Heparin / Green top
EDTA / Lavender top
Citrate / Light blue top
Oxalate / Gray top

Which oral anticoagulant medication is universally monitored in the laboratory using therapeutic values derived from light blue top tubes?
Warfarin
Heparin
Aspirin
Streptokinase

What is the required inversion count for a light blue top tube to ensure proper blood-anticoagulant mixing without triggering hemolysis?
Invert 3–4x
Invert 5–8x
Invert 8–10x
Invert 10–12x

What is the correct standard blood-to-anticoagulant ratio required for a light blue coagulation tube?
9:1 ratio
4:1 ratio
1:1 ratio
7:3 ratio

What is the correct standard blood-to-anticoagulant ratio required for a black sedimentation rate tube?
4:1 ratio
9:1 ratio
1:1 ratio
5:2 ratio

Which anticoagulant alternative is explicitly noted as preferred for arterial punctures and administered intravenously (Admin IV) in clinical settings?
Heparin
EDTA
Sodium citrate
Sodium fluoride

What is the expected clotting time required for a serum specimen inside a red/gray and gold SST tube?
30 mins
10 mins
45 mins
1 hour

What is the expected clotting time required for a serum specimen inside a yellow/gray and orange thrombin-based tube?
10 mins
30 mins
5 mins
45 mins

What is the correct chronological sequence for the CLSI order of draw based on the listed stoplight mnemonic?
Sterile (Yellow) → Light Blue → Red → SST (Gold) → PST (Light Green) → Green → Lavender → Gray
Sterile (Yellow) → Red → Light Blue → SST (Gold) → Green → PST (Light Green) → Gray → Lavender
Red → Sterile (Yellow) → Light Blue → SST (Gold) → PST (Light Green) → Lavender → Green → Gray
Light Blue → Sterile (Yellow) → Red → SST (Gold) → Green → PST (Light Green) → Lavender → Gray

Which tube option contains spray-dried K2EDTA and is specifically color-coded for blood banking and crossmatching procedures?
Pink
Lavender
White
Royal blue

Which molecular diagnostic tube relies on a white stopper and incorporates a physical gel barrier alongside EDTA to separate plasma?
White
Pink
Lavender
Black

Which collection tube contains sodium citrate but requires a 4:1 blood-to-anticoagulant ratio because it is designed specifically for Westergren sedimentation rates?
Black
Light blue
Pin
White

Which gel-barrier tube features a light green/black or light green stopper containing lithium heparin to yield plasma for chemistry testing?
Light green/black
Green
Tan
Royal blue

Which specific testing environment is uniquely suited for the royal blue top tube due to its ultra-trace element construction?
Plasma/chemistry/toxicology
Whole blood/hematology
Serum/microbiology culture
Plasma/glucose testing

What is the primary diagnostic function of the tan glass tube containing sodium heparin?
Plasma/lead testing
Plasma/chemistry/toxicology
Whole blood/blood bank
Plasma/molecular diagnostics

Which tube option relies on a tan plastic design containing K2EDTA to stabilize the specimen for blood lead analysis?
Tan (plastic)
Tan (glass)
White
Lavender (glass)

Which thrombin-activated rapid-clotting tube is identified by a yellow/gray and orange top or a solid orange top?
Yellow/gray and orange
Red/gray and gold
Red (plastic)
Red (glass)

Which serum separating tube (SST) uses a red/gray and gold stopper or a solid gold Hemogard closure?
Red/gray and gold
Yellow/gray and orange
Light green/black
White

Which specific tube type is physically composed of glass, contains no additives, and relies on the glass surface itself to activate the intrinsic clotting pathway?
Red (glass)
Red (plastic/Hemogard)
Lavender (glass)
Lavender (plastic)

Which specific tube option contains a silica clot activator sprayed onto the interior walls because its plastic material cannot naturally trigger clot formation?
Red (plastic/Hemogard)
Red (glass)
Lavender (plastic)
Lavender (glass)

Which version of the hematology collection tube contains the anticoagulant K3EDTA in a liquid formulation?
Lavender (glass)
Lavender (plastic)
Tan (glass)
Tan (plastic)

Which version of the hematology collection tube contains a spray-dried formulation of K2EDTA inside its structural casing?
Lavender (plastic)
Lavender (glass)
Tan (glass)
Tan (plastic)

Which lead testing tube option utilizes a glass structure paired with a sodium heparin anticoagulant matrix?
Tan (glass)
Tan (plastic)
Royal blue
Green

Which lead testing tube option utilizes a plastic structure paired with a K2EDTA anticoagulant matrix?
Tan (plastic)
Tan (glass)
White
Lavender (glass)

Which light blue tube option contains a specialised mixture of thrombin and soybean trypsin used to evaluate fibrin degradation products?
Light blue (plastic with thrombin and soybean trypsin)
Light blue (glass with sodium citrate)
Black (glass with sodium citrate)
Yellow (glass with acid citrate dextrose)

Which serum separation tube (SST) uses a clot activator alongside a separation gel and is capped with a red/gray and gold stopper?
Red/gray and gold
Yellow/gray and orange
Light green/black
White

Which rapid-acting serum tube contains thrombin as its active clot activator and is identified by a yellow/gray and orange closure?
Yellow/gray and orange
Red/gray and gold
Red (plastic)
Red (glass)

Which plasma separation tube (PST) incorporates lithium heparin and a gel barrier, finished with a light green/black or light green top?
Light green/black
Green
Tan (glass)
Royal blue