3.1 Processing, Testing & Labeling

Specialist in Blood Banking, SBB ASCP

Track your progress as you read

Finished sections get a check mark.

1 Introduction & Exam Overview

1.1 Current Exam Facts 1.2 Eligibility Routes & Credential Maintenance 1.3 Study Strategy for SBB

2 Donors & Collection

2.1 Donor Qualification 2.2 Collection Methods & Adverse Reactions 2.3 Special Donations

3 Processing, Storage & Component QC

3.1 Processing, Testing & Labeling 3.2 Storage, Transport & Expiration 3.3 Blood Component Quality Control

4 Red Cell & Modified Components

4.1 Whole Blood & Red Blood Cells 4.2 Leukocyte-Reduced, Washed, Frozen & Rejuvenated RBCs 4.3 Irradiated Components 4.4 Granulocytes

5 Platelets, Plasma & Cellular Products

5.1 Platelets 5.2 Plasma & Cryoprecipitated AHF 5.3 Apheresis Products & Fractionation Products 5.4 Hematopoietic Progenitors

6 Genetics, ABO & Rh

6.1 Blood Group Genetics & Molecular Inheritance 6.2 ABO & Lewis Systems 6.3 Rh System 6.4 MNS, P1PK/Globoside & Ii

7 Other Blood Groups & Role in Transfusion

7.1 Kell, Kidd, Duffy & Lutheran 7.2 Other Systems & High/Low-Prevalence Antigens 7.3 HLA, Platelet-Specific & Granulocyte Antigens 7.4 Immunogenicity & Antigen Prevalence

8 Immunology Foundations

8.1 Immune Response 8.2 Immunoglobulins 8.3 Antigen-Antibody Interactions 8.4 Complement

9 Physiology, Hemostasis & HDFN

9.1 Physiology of Blood 9.2 Hemostasis and Coagulation 9.3 HDFN Pathophysiology & Detection 9.4 HDFN Treatment & Prevention

10 Cytopenias & Transplantation

10.1 Immune & Nonimmune Anemia 10.2 Thrombocytopenia & Neutropenia 10.3 Solid Organ Transplantation Support 10.4 Hematopoietic Progenitor Cell Transplantation

11 Routine Serologic Testing

11.1 Blood Grouping Tests 11.2 Antibody Detection & Crossmatch 11.3 Antibody Identification & Clinical Significance 11.4 Direct Antiglobulin Testing & Reagents

12 Special Serologic Methods

12.1 Enzymes, Enhancement Media & Lectins 12.2 Adsorptions, Elutions & Titrations 12.3 Cell Separations, Neutralization & Thiol Reagents 12.4 Chloroquine Diphosphate & EDTA-Glycine Acid

13 Molecular Platforms & Serologic QA

13.1 Molecular Blood Group Techniques 13.2 ELISA, Immunofluorescence, Solid Phase & Column Agglutination 13.3 Serologic Quality Assurance

14 Indications, Component Therapy & PBM

14.1 Indications for Transfusion 14.2 Component Therapy 14.3 Blood Administration & Patient Blood Management

15 Adverse Effects of Transfusion

15.1 Immunologic Transfusion Reactions 15.2 Nonimmunologic Reactions 15.3 Transfusion-Transmitted Diseases

16 Apheresis & Extracorporeal Circulation

16.1 Therapeutic Apheresis 16.2 Extracorporeal Circulation

17 Quality, Safety, Math & Instrumentation

17.1 Quality Assessment & Troubleshooting 17.2 Laboratory Safety 17.3 Laboratory Mathematics 17.4 Instrumentation

18 Laboratory Administration (SBB Only)

18.1 Financial Management 18.2 Operations & Information Technology 18.3 Personnel, Education & Training 18.4 Quality Management, Risk & Tissue Management

3.1 Processing, Testing & Labeling

Key Takeaways Explain This Topic AI

Every donation undergoes mandatory ABO/Rh typing, an antibody screen, and a full infectious disease testing panel before any component can be released for transfusion

A repeat-reactive infectious disease marker on a first-time donor triggers donor notification, deferral, and (for most markers) supplemental or confirmatory testing before re-entry is possible

ISBT-128 replaced the older Codabar system and encodes donation number, product code, ABO/Rh, and expiration in machine-readable barcodes to reduce mislabeling errors

Labeling requirements are FDA (21 CFR 606, 610, 660) and AABB Standards-driven; a unit missing a required label element cannot be shipped or transfused

Look-back and quarantine procedures require retrieval of previously issued components from a donor who later tests repeat-reactive

Last updated: July 2026

Processing, Testing & Labeling

Quick Answer: Before any donated unit can be released for transfusion, it must be centrifuged into components, typed for ABO/Rh, screened for unexpected antibodies, and tested against a full infectious disease marker panel. Every result must resolve favorably (or be appropriately worked up) before the unit is labeled with an ISBT-128 barcode and released. This section covers the required testing panel, how repeat-reactive results are handled, and the FDA/AABB labeling elements a compliant unit must carry.

From Whole Blood to Components

Within hours of collection, whole blood is separated by differential centrifugation into its components — red blood cells, platelets, and plasma — because each component has different storage requirements and clinical uses. A "hard spin" separates plasma from the cellular layer; platelet-rich plasma can then be given a second "light spin" to separate platelet concentrate from platelet-poor plasma. Processing must occur within specified time windows relative to collection (commonly within 6–8 hours for platelet production from whole blood, and within 8 hours if plasma is to be used for coagulation factor products) because holding temperature and elapsed time directly affect factor VIII activity and platelet viability. Facilities validate their own hold times and centrifugation protocols against AABB Standards and FDA guidance rather than relying on a single universal number, since equipment and protocols vary.

I.B — Mandatory Testing Panel

Every donation, no matter how many times the donor has given before, undergoes the same core testing panel prior to release:

ABO and Rh Typing

Forward (direct) typing determines the antigens present on the donor's red cells using anti-A and anti-B reagents; on first-time donors , AABB Standards require confirmatory testing on a separate sample to verify ABO group before labeling, as a safeguard against sample mix-up. Rh(D) typing uses anti-D reagent; donors whose cells are weakly or discrepantly reactive must be resolved before the unit can be labeled Rh-positive or Rh-negative — many facilities label discrepant results as Rh-positive out of caution (a falsely-labeled Rh-negative unit given to an Rh-positive recipient is far more consequential than the reverse) or perform weak D testing to resolve the discrepancy.

Antibody Screen

Donor plasma or serum is screened against reagent red cells to detect clinically significant unexpected antibodies (e.g., anti-K, anti-Jka). A positive screen requires antibody identification; if a clinically significant antibody is identified, plasma and platelet products from that donation are typically restricted or the donor is flagged so recipient crossmatching accounts for it. RBC units themselves are not affected by donor antibodies since the plasma is removed, but a donor's own antibody history matters for donors who plan to give again.

Infectious Disease Testing Panel

FDA-mandated infectious disease testing on every donation (conceptually, not exhaustively) includes:

Marker Category What Is Tested Purpose
HIV Anti-HIV-1/2 antibody + HIV-1 NAT Detects antibody-positive and early window-period infection

Hepatitis B HBsAg, anti-HBc (total), HBV NAT Detects active surface antigenemia, past/chronic exposure, and early window-period infection

Hepatitis C Anti-HCV antibody + HCV NAT Detects antibody-positive and early window-period infection
HTLV-I/II Anti-HTLV-I/II antibody Detects retrovirus associated with leukemia/lymphoma and myelopathy

Syphilis Serologic test (e.g., treponemal or nontreponemal) Detects Treponema pallidum exposure; also a proxy behavioral-risk marker

West Nile Virus NAT Seasonal/regional arbovirus screening

Chagas disease Anti- T. cruzi antibody Required at least once per donor (per current FDA guidance for repeat donors); parasitic disease with long dormant infectivity

Zika virus NAT (during applicable guidance periods) Emerging arbovirus screening per FDA guidance in effect
Babesia NAT/antibody testing in endemic regions Region-dependent per current FDA requirements

Bacterial contamination (platelets) Culture or rapid bacterial detection Platelets stored at room temperature are the highest-risk component for bacterial growth

Nucleic acid testing (NAT) shortens the infectious window period compared to antibody/antigen testing alone by detecting viral genetic material directly, which is why HIV, HBV, and HCV each pair a serologic test with a NAT assay. Exact required markers and testing technologies are FDA-guidance-dependent and updated periodically — candidates should know the categories and rationale (antibody vs. antigen vs. NAT, window-period reduction) rather than memorizing a single frozen list, since guidance documents are revised as epidemiology and assay technology change.

Repeat-Reactive Results, Confirmatory Testing, and Donor Deferral

A donation with a reactive infectious disease screening result is not automatically "positive" — it is repeat-reactive if the initial reactive result is confirmed on retesting (per the assay's package insert protocol, often testing the same sample in duplicate). A confirmed repeat-reactive result triggers:

Unit quarantine and discard — the unit and all associated components are not released
Donor notification — the facility must notify the donor per FDA requirements
Donor deferral — indefinite or permanent deferral depending on the marker and confirmatory result

Look-back investigation — for markers with recognized window periods, prior donations from the same donor may need to be traced, and previously transfused recipients or unused components identified, since the donor may have been in an infectious window period during an earlier, seemingly-negative donation

Supplemental/confirmatory testing — additional, more specific assays (e.g., for HBV, testing for anti-HBs and additional markers) to distinguish true infection, resolved past infection, or biological false-positivity, which matters for whether a donor may ever be re-entered

Donor re-entry after a repeat-reactive screening result (in the absence of confirmed infection) is possible under FDA-defined re-entry protocols requiring a waiting period and additional negative testing, but a confirmed positive result (e.g., confirmed HIV or HCV infection) results in permanent deferral.

I.B — ISBT-128 Labeling

ISBT-128 (International Society of Blood Transfusion 128) is the globally standardized labeling system that replaced the older Codabar system in the U.S. It uses linear and 2D barcodes to encode, in machine-readable form:

Donation identification number (DIN) — a unique 13-character identifier tying the unit to donor, collection facility, and collection date

Product code — a 5-character code (from a standardized product description code database) identifying exactly what the component is (e.g., irradiated, leukocyte-reduced, specific anticoagulant)

ABO/Rh group
Expiration date (and, where applicable, expiration time)
Special attributes (e.g., CMV-negative, irradiated) via additional facility-applied labels

ISBT-128's key advantage over Codabar is a single, unambiguous global numbering scheme that prevents donation-number collisions across facilities and countries, and its barcode structure supports scan-based verification at multiple checkpoints (collection, processing, labeling, issue, bedside administration) to reduce transcription and mislabeling errors — historically one of the most dangerous categories of transfusion error because a mislabeled ABO group can cause a fatal hemolytic transfusion reaction.

FDA/AABB Required Label Elements

A compliant final container label (per 21 CFR 606.121 and AABB Standards) must display, at minimum:

Required Element Notes
Proper name of the component e.g., "Red Blood Cells," "Leukocytes Reduced"
Donation identification number ISBT-128 DIN, unique and traceable
ABO group and Rh type Confirmed per testing above
Expiration date/time Determined by anticoagulant/additive solution and storage conditions
Volume (where applicable)
Name/address of collecting facility Registration number
Anticoagulant/additive solution e.g., CPD, CPDA-1, AS-1
Storage temperature requirement

Statement referencing donor testing Standard cautionary statement that the unit has been tested and found suitable, or the applicable biohazard legend if untested/not intended for transfusion

"Rx only" / prescription legend Federal law restricts to physician order
Autologous/directed donation statement If applicable, with recipient identification

Any unit missing a required label element, or with an internal label discrepancy (e.g., ABO on the bag doesn't match the testing record), must be investigated and cannot be released until resolved — this is a common quality control hold point audited during inspections.

Practical Test-Taking Focus

SBB exam items on this topic tend to test conceptual understanding of why a testing or labeling step exists (window period reduction, mislabel prevention, donor safety) rather than requiring memorization of every current FDA-required marker, since guidance is periodically updated. Know the categories (serology vs. NAT), the purpose of confirmatory/supplemental testing, and the function of ISBT-128 versus Codabar.