Page 707 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

CHAPTER 32 ■ Laboratory Manual: Manual Procedures in Hematology 691

SPECIAL STAINS (continued)

Clinical Applications irreversible a ition o eoxynucleoti es to the 3′-hy roxy

Tis cytochemical stain in conjunction with other testing is groups on the en o DNA. T e primary metho s o etec-

use ul in the i entif cation o myelogenous an myelomono- tion are immuno uorescence an immunoperoxi ase using

cytic leukemias. a monoclonal antibo y.

T is proce ure in CLSI ormat is provi e on this book’s is a cell marker oun on immature an neoplastic

companion Web site at thepoint.lww.com/ urgeon6e. cells requently seen in leukemic states.

Clinical Applications
TERMINAL DEOXYNUCLEOTIDYL TRANSFERASE

TEST T is proce ure is use ul in i enti ying lymphoblastic cells on
peripheral bloo an /or bone marrow smears.
Principle T is proce ure in CLSI ormat is provi e on this book’s

erminal eoxynucleoti yl trans erase ( ) is a non– companion Web site at thepoint.lww.com/ urgeon6e.

template- irecte DNA polymerase that catalyzes the

COAGULATION PROCEDURES

In coagulation testing, replicate analysis is requently per- 1. It has a closer osmolality to plasma an pro uces more

orme . However, in a stu y o replicate testing, it was con- accurate activate partial thromboplastin time (AP )

clu e that repeat testing oes not enhance the precision or results when patients are being treate with heparin.

the accuracy o coagulation tests. Accuracy an precision are 2. T is citrate concentration is use as the mean o the nor-

controlle by quality assurance proce ures, such as requent mal range in the calculation o the international normal-

calibration checks an multilevel commercial controls, as ize ratio. Other anticoagulants (e.g., heparin, ED A, or

well as the practices escribe below. oxalate) shoul not be use .

Specimen Quality T e intro uction o plastic tubes or sa ety reasons

All coagulation testing critically epen s on the quality o requires that new re erence ranges or all coagulation assays

the specimen. Minimum tissue trauma an the avoi ance be establishe . At least 10 emale an 10 male patients who
o hemolysis are essential. Proper phlebotomy techniques are in the laboratory’s patient population an who are not

escribe in Chapter 2 must be strictly ollowe . receiving anticoagulation therapy shoul be teste to estab-
lish a re erence range.
Special Collection Techniques Because o the importance o the ratio o bloo to anti-

o re uce the possibility o intro ucing tissue thromboplas- coagulant, the proper vacuum in an evacuate tube must be

tin into a whole bloo sample an the subsequent utiliza- maintaine . T e expiration ate on the tube container nee s

tion o certain actors with clot ormation, certain techniques to be monitore . I tubes are store in seale metal contain-

shoul be ollowe . Specimens collecte or coagulation ers, precautions shoul be taken to monitor the premature

stu ies are not normally rawn initially, i multiple samples loss o the tubes’ vacuum. ubes are store best in open con-

are collecte . I a single sample is collecte using an evac- tainers in an upright position.

uate tube, a small amount o bloo shoul be allowe to T e ratio o 9:1 in a specimen anticoagulate with so ium

enter the plastic nee le hol er be ore collecting bloo in the citrate is achieve with a properly collecte specimen i a

tube. Nonwettable evacuate tubes shoul be use to pre- patient’s PCV is between 0.20 an 0.60 L/L. However, in poly-

vent activation o actors XII an VII by the glass walls o the cythemic or grossly anemic patients, a correction in the amount

container. o anticoagulant or the amount o bloo rawn must be ma e.

I a sample is collecte using the syringe technique, two o etermine the amount of anticoagulant in extreme

syringes are use . Approximately 1 mL o venous bloo is cases, the ollowing correction ormula is use :

collecte in the f rst tube, an this syringe is isconnecte

.
−
rom the nee le hub. Imme iately, a secon syringe is con- 000185 × volume o bloo (mL ) × 100 patient’s
necte to the hub o the nee le, an the specimen is collecte spacke cell volume

in this syringe.

o etermine the amount of whole blood nee e ,
Anticoagulants

So ium citrate (3.2%) is the anticoagulant o choice (see 60 × 45
.
Chapter 2). T e 3.2% citrate concentration has several 100 − patient’s packe cell volume

a vantages:

(continued)