210 Concise Book of Medical Laboratory Technology: Methods and Interpretations FIGS. 9.4A TO C: (A) Sahli’s hemoglobinometer; (B) Hb pipette; (C) Stirrer acid-blood in the tube. Add distilled water until a match is obtained with the brown glass standard (comparator) provided. Read the lower level of fluid meniscus on g%

 

of the sample—a particularly important factor with

ESR determinations and coagulation studies, which

can be seriously distorted by microbial growth in the

citrate solution. The laboratory personnel derive the

maximum benefit (by use of vacutainers) though the

physician is assisted only indirectly in the form of

quality reports. Also available are vacutainer culture

systems, where blood is injected into the culture

media directly without even coming in contact with

atmosphere (Fig. 9.3).

¾ Table 9.1 gives color codes for the Vacutainer systems

and in all cases different volume containers are

available—from 2 to 15 mL.

BD Vacutainer

 Order of Draw for Multiple

Tube Collections

Designed for Your Safety

Reflects change in CLSI recommended order of draw

(H3-A5, Vol 23, No 32, 8.10.2)

Clinical Hematology 209

TABLE 9.1: Vacutainer color codes and their usage

Stopper color code Additive Used for Remarks

 1. Gray and red Inert polymer

Barrier material tubes

Chemistry Serum separation

 2. Yellow and red None Chemistry Clot activator tubes

 3. Red None Chemistry Silicone coated interior

 4. Red/orange green None Chemistry -

 5. Yellow None Chemistry Silicon-coated interior

 6. Royal blue None/heparin/EDTA Toxicology and nutrition studies, e.g.

trace elements, heavy metals, etc.

 7. Brown Sodium heparin Lead determination

 8. Yellow black Thrombin (NIH) For stat procedures as thrombin

hastens clotting and therefore quick

serum separation

 9. Gray Sodium fluoride/ Iodoacetic lithium potassium

oxalate- NaF/EDTA-NaF/ Thymol NaF

For glucose estimation

10. Green Sodium heparin

Lithium heparin

Ammonium heparin

For chemistry or cytology

11. Blue Sodium citric acid For coagulation studies

12. Lavender EDTA For hematology studies

13. Yellow ACD solution A

ACD solution B

ACDP solution Alsever’s solution

For blood banking

For blood banking

14. Green Na heparin LE cell preparation Prelabeled

15. Gray/Black Gives citrate

Blood a ratio of 1:4

For ESR estimation by Westergren’s

method

Prelabeled

16. Blue Ammonium oxalate and potassium oxalate in a

ratio of 6:4

For ESR estimation by Wintrobe’s

methods

Prelabeled

17. Yellow Sodium polyane tholesulfonate 0.35% in 0.85%

sodium chloride

For microbiology Prelabeled

Closure Color Collection Tube Mix by Inverting

BD Vacutainer ® Blood Collection Tubes (glass or plastic)

• Blood Cultures – SPS 8 to 10 times

• Citrate Tube (Fig. 9.3) 3 to 4 times

 or •  BD Vacutainer SST™

Gel Separator Tube

•  Serum Tube (glass or

plastic)

•  BD Vacutainer Rapid

Serum Tube (RST)

5 times

5 times (plastic)

none (glass)

5 to 6 times

 or •  BD Vacutainer PST™

Gel Separator Tube With

Heparin

• Heparin Tube

8 to 10 times

8 to 10 times

 or • EDTA Tube 8 to 10 times

•  BD Vacutainer PPT™

Separator Tube K2EDTA

with Gel

8 to 10 times

• Fluoride (glucose) Tube 8 to 10 times

Contd..

Note: Always follow your facility’s protocol for order of draw

Handle all biologic samples and blood collection “sharps”

(lancets, needles, luer adapters and blood collection sets)

according to the policies and procedures of your facility.

Obtain appropriate medical attention in the event of any

exposure to biologic samples (for example, through a

puncture injury) since they may transmit viral hepatitis,

HIV (AIDS), or other infectious diseases. Utilize any built-

210 Concise Book of Medical Laboratory Technology: Methods and Interpretations FIGS. 9.4A TO C: (A) Sahli’s hemoglobinometer; (B) Hb pipette; (C) Stirrer

acid-blood in the tube. Add distilled water until a match

is obtained with the brown glass standard (comparator)

provided. Read the lower level of fluid meniscus on g%

side of the tube.

Report hemoglobin in g/100 mL of blood. If hemoglobin

is less than 2 g%, take double the quantity of blood and

divide the result by 2. If hemoglobin concentration

is extremely high dilute blood with equal amount of

normal saline, take the reading and multiply by 2. This

method, however, does not estimate carboxyhemoglobin,

methemoglobin and sulfhemoglobin. Non-hemoglobin

substances (protein, lipids) in plasma and cell stroma

may influence the color of blood diluted with acid. It is,

therefore, not a very satisfactory method.

Cyanmethemoglobin Method

(Drabkin’s solution and the standard available from Coral

Clinical Systems, Goa)

Drabkin’s Reagent

In 1000 mL of deionized water are mixed:

¾ Potassium ferricyanide: 400 mg

¾ Potassium dihydrogen phosphate: 280 mg

¾ Potassium cyanide: 100 mg

¾ Nonidet (non ionic detergent): 1 mL.

This reagent can be stored in a polythene container.

Concentrated stock solutions can also be prepared and

diluted accordingly when needed.

Pipette carefully and take care not to discard cyanide

solutions into sinks or receptacles containing acid (to

prevent formation of hydrocyanic acid). To 5 mL of

in used needle protector if the blood collection device

provides one. BD does not recommend reshielding used

needles, but the policies and procedures of your facility

may differ and must always be followed. Discard any blood

collection “sharps” in biohazard containers approved for

their disposal.

When using a winged blood collection set for

venipuncture and a coagulation (citrate) tube is the first

specimen tube to be drawn, a discard tube should be drawn

first. The discard tube must be used to fill the blood collection

set tubing’s “dead space” with blood but the discard tube

does not need to be completely filled. This important step

will ensure proper blood to additive ratio. The discard tube

should be a nonadditive or coagulation tube.

HEMOGLOBIN

Hemoglobin (Hb) is the main constituent of the RBCs and

carries out the important function of transportation of

oxygen from lungs to various parts of the body. To a lesser

extent, it transports back carbon dioxide from the body to

the lungs. When fully saturated, each gram of hemoglobin

holds approximately 1.34 mL of oxygen. The red cell mass

of an adult contains approximately 600 g of hemoglobin,

capable of carrying 800 mL of oxygen.

Hemoglobin Estimation: Sahli’s Method: (Sahli’s

Hemoglobinometer) (Fig. 9.4)

This is based on conversion of hemoglobin to acid hematin,

which has brown color. Fill hemoglobin tube till 20 mark

with N/10 HCl. To this, add blood sucked till the specific

mark (20 μL) on the hemoglobin pipette and wait for 5–45