CHT Cheat Sheet 2026

The 30 highest-yield CHT facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is a key aspect of Laboratory Techniques & Testing Procedures? → Laboratory Techniques & Testing Procedures standard
2. In NGS-based HLA typing, what is a key advantage over Sanger sequencing? → Resolves phase ambiguities and provides allele-level phased genotypes
3. Which document describes the step-by-step procedure for performing a test, including safety precautions, reagents, and interpretation criteria? → Standard Operating Procedure (SOP)
4. The antihuman globulin (AHG)-enhanced CDC crossmatch increases sensitivity by: → Crosslinking IgG bound to cell-surface HLA, increasing complement-fixing complexes
5. What is a key aspect of Data Interpretation & Clinical Application? → Data Interpretation & Clinical Application standard
6. Which test is used to measure the strength of donor-specific antibodies in mean fluorescence intensity (MFI) units? → Single Antigen Bead (SAB) assay
7. What is a key aspect of Data Interpretation & Clinical Application? → Data Interpretation & Clinical Application standard
8. EDTA is sometimes added to crossmatch reaction tubes in order to: → Chelate divalent cations to inhibit complement activation
9. Which HLA gene is encoded outside the classical MHC class I region yet is important in NK cell regulation? → HLA-E
10. What is the definition of 'brain death' relevant to deceased donor organ procurement? → Irreversible cessation of all functions of the entire brain, including the brainstem
11. What is the primary function of beta-2 microglobulin (β2m) in HLA class I molecules? → Stabilizes the alpha chain and is required for surface expression
12. Which immunoglobulin subclass of IgG most efficiently activates complement and is most associated with acute AMR? → IgG1 and IgG3
13. Which biological safety level (BSL) is appropriate for routine work with human blood and tissue specimens in a histocompatibility lab? → BSL-2
14. HLA molecules are encoded by genes in which genomic region? → Major Histocompatibility Complex (MHC)
15. Which best describes an auto-crossmatch and its clinical use? → Testing recipient serum against the recipient's own lymphocytes
16. In a complement-dependent cytotoxicity (CDC) crossmatch, cell death is assessed by: → Exclusion of a vital dye such as eosin Y or trypan blue
17. Why is HLA typing necessary before transplantation? → To identify compatible tissue
18. Which HLA class II loci are considered the most polymorphic and clinically significant for transplantation? → HLA-DRB1 and HLA-DQB1
19. Pronase treatment of donor lymphocytes before CDC crossmatch testing enhances sensitivity by: → Cleaving complement regulatory proteins (CD55, CD59) from the cell surface
20. An HLA allele designated HLA-A*02:01 indicates what level of resolution? → Second-field (allele-level) resolution
21. What is a 'zero-antigen mismatch' kidney in UNOS allocation policy? → A kidney with no mismatches at HLA-A, -B, and -DR compared to the recipient
22. Which type of rejection occurs within minutes to hours after transplantation and is mediated by preformed donor-specific antibodies? → Hyperacute rejection
23. Which allocation principle ensures that the sickest patients (greatest medical urgency) receive priority for certain organs like hearts and livers? → Medical urgency status (e.g., Status 1A/1B for hearts, MELD score for livers)
24. Which OSHA standard is most directly relevant to worker safety in the histocompatibility laboratory when handling patient specimens? → Bloodborne Pathogens Standard (29 CFR 1910.1030)
25. Which type of HLA typing method directly determines the nucleotide sequence of HLA alleles? → Sequence-Based Typing (SBT/SBT-NGS)
26. Which test can confirm the clinical relevance of DSA detected by SAB assay by evaluating actual cell lysis in the presence of complement? → CDC crossmatch
27. What is a key aspect of Data Interpretation & Clinical Application? → Data Interpretation & Clinical Application standard
28. What is the 'Luminex bead C1q assay' used to assess? → Whether HLA antibodies can fix complement (C1q) and are therefore more likely to cause AMR
29. What is a key aspect of Quality Assurance & Regulatory Compliance? → Quality Assurance & Regulatory Compliance standard
30. What is a key aspect of Data Interpretation & Clinical Application? → Data Interpretation & Clinical Application standard