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{{Memorization-worthy}} For the most likely types of cases and/or questions that you may be responsible for, know where to find local '''policies and procedures''', and have a good idea of '''[[Consultation|whom to ask]]''' for further advice. Make sure you have access and/or contact details for '''whenever and wherever''' you are likely to need them.
Preferably have at least a quick look at policies and procedures so that you have an idea of what kind of answers you will find there when needed.
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==Hematopathology==
{{Learning hematopathology}}

==Sample tube types==
The following is an overview of the main types of sample tube types, organized by order of draw (the recommended sequence by which fluid is drawn) during blood draws:
{|class="wikitable"
! Tube cap color or type in order of draw !! Additive !! Usage and comments
|-
| '''Blood culture''' bottle || '''Sodium polyanethol sulfonate''' (anticoagulant) and '''growth media''' for microorganisms|| Usually drawn first for minimal risk of contamination.<ref>{{cite book|first1=KD |last1=Pagana|first2=TJ |last2=Pagana|first3=TN |last3=Pagana|title=Mosby's Diagnostic and Laboratory Test Reference - E-Book|url=https://books.google.com/books?id=J7eXBAAAQBAJ&pg=PR13|date=19 September 2014|publisher=Elsevier Health Sciences|isbn=978-0-323-22592-2|p=xiii}}</ref> Two bottles are typically collected in one blood draw; one for aerobic organisms and one for anaerobic organisms.<ref>{{cite book|title=Clinical Microbiology Procedures Handbook|url=https://books.google.ca/books?id=pEL2DwAAQBAJ&pg=PT140|date=6 August 2020|publisher=Wiley|isbn=978-1-55581-881-4|chapter=Chapter 3.4.1: Blood cultures; general detection and interpretation}}</ref>
|-
!style="background: skyblue"| Light blue
| Sodium '''citrate''' (anticoagulant) || '''Coagulation tests''' such as prothrombin time (PT) and partial thromboplastin time (PTT) and thrombin time (TT). Tube must be filled 100%.
|-
!style="background: red; color: white"| Plain red
| '''No additive''' || '''Serum''': Total complement activity, cryoglobulins
|-
!style="background: goldenrod"| Gold (sometimes red and grey "tiger top"<ref>{{Cite web|date=June 2019|title=Test Tube Guide and Order of Draw|url=https://www.guthrie.org/sites/default/files/GMG_708_0002%20Test%20Tube%20Chart%20and%20Order%20of%20Draw%20Guide%20Attachment%20A%20%20%206-25-19.pdf|url-status=live|website=Guthrie Laboratory Services}}</ref>)
| '''Clot activator''' and '''serum separating''' gel<ref>{{cite web|url=http://www.pathology.uci.edu/services/specimen-containers.asp|title=Specimen requirements/containers|website=Pathology & Laboratory Medicine, UCI School of Medicine|access-date=2020-09-10}}</ref> || '''Serum-separating tube''': Tube inversions promote clotting. Most chemistry, endocrine and serology tests, including hepatitis and HIV.
|-
!style="background: mediumseagreen; color: white"| Dark green
| Sodium '''heparin''' (anticoagulant) || Chromosome testing, HLA typing, ammonia, lactate
|-
!style="background: lightgreen"| Light green
| Lithium '''heparin''' (anticoagulant) || '''Plasma'''. Tube inversions prevent clotting
|-
!style="background: MediumOrchid"| Lavender ("purple")
| '''EDTA''' (chelator / anticoagulant) || '''Whole blood''': CBC, ESR, Coombs test, platelet antibodies, flow cytometry, blood levels of tacrolimus and cyclosporin
|-
!style="background: pink"| Pink
| '''EDTA''' (chelator / anticoagulant) || '''Blood typing''' and cross-matching, direct Coombs test, HIV viral load
|-
!style="background: royalblue; color: white"| Royal blue
| '''EDTA''' (chelator / anticoagulant) || Trace elements, heavy metals, most drug levels, toxicology
|-
!style="background: tan"| Tan
| '''EDTA''' (chelator / anticoagulant) || '''Lead'''
|-
!style="background: gray; color: white"| Gray
| 
*Sodium '''fluoride''' (glycolysis inhibitor) 
*Potassium '''oxalate''' (anticoagulant)<ref name="pmid1644639">{{cite journal| vauthors=Castellini MA, Castellini JM, Kirby VL| title=Effects of standard anticoagulants and storage procedures on plasma glucose values in seals. | journal=J Am Vet Med Assoc | year= 1992 | volume= 201 | issue= 1 | pages= 145–8 | pmid=1644639 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1644639  }} </ref>
| '''Glucose test|Glucose''', lactate<ref name="DasguptaSepulveda2019">{{cite book|author1=Amitava Dasgupta|author2=Jorge L. Sepulveda|title=Accurate Results in the Clinical Laboratory: A Guide to Error Detection and Correction|url=https://books.google.com/books?id=HB2kDwAAQBAJ&pg=PA131|date=20 July 2019|publisher=Elsevier Science|isbn=978-0-12-813777-2|page=131}}</ref>
|-
!style="background: yellow"| Yellow
| '''Acid-citrate-dextrose A''' (anticoagulant) || Tissue typing, DNA studies, HIV cultures
|-
!style="background: pearl"| Pearl ("white")
| '''Separating gel''' and (K<sub>2</sub>)'''EDTA''' || '''PCR''' for adenovirus, toxoplasma and HHV-6
|}

==Lab management==
Lab management is essentially about handling each of the extremely various lab-related situations that arise, and can generally be achieved by:
*'''Common sense'''
*Gathering enough '''information''' before a decision
:*Identifying what questions needs answering
:*Asking proper expertise and/or looking up relevant information in proper sources (see [[learning pathology]]), which may include local protocols as well as policies of accrediting organizations of the department (which are generally more stringent than the national or regional laws).
For location-specific issues, it generally helps to personally '''come and see''' the location at hand.
{{Question|title=Retention time|subsection=yes}}(You may skip this question if you don't expect to ever be part of laboratory management in the US.)

You work in a pathology department in the United States, which is accredited by the College of American Pathologists (CAP). Your local procedure manual states that non-forensic paraffin-embedded blocks must be retained for at least 10 years before being thrown away. In order to save storage space, one suggestion that gets brought up is to reduce the retention time to 5 years. You look up the issue, and find that federal U.S. law (the Clinical Laboratory Improvement Amendments; CLIA) states that such blocks must be retained for at least 2 years. Is it acceptable to finish the look-up here, and agree to reduce the retention time of non-forensic paraffin-embedded blocks to 5 years in this department?
*'''Answer''': This pathology department is accredited by CAP, whose requirements commonly exceed those of CLIA, in this case stating at least 10 years for non-forensic paraffin-embedded blocks. Therefore, it is ''not'' acceptable to relax minimum retention times without first having had a look at CAP requirements, if the lab is accredited by it (don't assume it isn't without checking). Thus, the answer to this question is: no. Furthermore, state laws need to be considered as well, as they may exceed those of CLIA.

For quick look-up in the future, the following are the most relevant retention times, as given by CLIA<ref name=CLIA>{{cite web|url=https://www.law.cornell.edu/cfr/text/42/493.1105|title=42 CFR § 493.1105 - Standard: Retention requirements.|website=Cornell Law School}} [68 FR 3703, Jan. 24, 2003; 68 FR 50723, Aug. 22, 2003]</ref> as well as by CAP<ref name=CAP>{{cite web|url=https://elss.cap.org/elss/ShowProperty?nodePath=/UCMCON/Contribution%20Folders/WebApplications/pdf/retention-laboratory-records-and-materials.pdf|title=CAP Policy Manual - Policy PP. Minimum Period of Retention of Laboratory Records and Materials|website=CAP.org}} Adopted August 1995. Revised September 2020</ref> (more comprehensive lists are available in their sources):
{|class=wikitable
!rowspan=4| Microscopy slides
| Histology and non-forensic autopsy || 10 years<ref name=CLIA/>
|-
| Forensic autopsy || Indefinitely<ref name=CLIA/>
|-
| Cytology, fine needle aspiration || 10 years<ref name=CAP/>
|-
| Cytology, apart from fine needle aspiration || 5 years<ref name=CLIA/>
|-
!rowspan=2| Paraffin-embedded blocks 
| Non-forensic || 2<ref name=CLIA/> or 10 years<ref name=CAP/>
|-
| Forensic || Indefinitely<ref name=CLIA/>
|-
!rowspan=2| Requisition forms and test reports
| Pathology reports || 10 years<ref name=CLIA/>
|-
| Other || 2 years<ref name=CLIA/>
|-
!rowspan=3| [[Blood bank]] records 
| Quality control records || 5 years<ref name=CAP/>
|-
| Donor and recipient records || 10 years<ref name=CAP/>
|-
| Records of indefinitely deferred donors || Indefinitely<ref name=CAP/>
|-
!colspan=2| Wet tissues 
| Until report is completed<ref name=CLIA/> or 2 weeks thereafter<ref name=CAP/>
|-
!colspan=2| Proficiency testing records and quality management/quality control records (except for blood bank)
| 2 years<ref name=CLIA/>
|-
!colspan=2| Discontinued procedures 
| 2 years<ref name=CLIA/>
|-
!colspan=2| [[Blood smear]]s and other body fluid smears, microbiology slides (including Gram stains)
| 7 days<ref name=CAP/>
|-
!colspan=2| [[Flow cytometry]] plots 
| 10 years<ref name=CAP/>
|}
{{Question-end}}
<noinclude>
===Test indication===
In simplified terms, the indication for a test on an individual is primarily determined by its overall positive impact, referred to as the ''net benefit''. Tests are selected when the anticipated benefit outweighs the expected harm. The net benefit may roughly be estimated by:

*b<sub>n</sub> = Λp * r<sub>i</sub> * ( b<sub>i</sub> - h<sub>i</sub> ) - h<sub>t</sub>

, where:
* ''b<sub>n</sub>'' is the net benefit of conducting a test
* ''Λp'' which represents the absolute difference between the pre- and posttest probabilities of certain conditions, like diseases, that the test is expected to detect. This absolute difference is significantly influenced by the test's power, characterized by parameters such as sensitivity, specificity, or likelihood ratio. Additionally, the pre-test probability plays a role, with lower pre-test probabilities resulting in diminished absolute differences. This means that powerful tests may show a low absolute difference for unlikely conditions, while less powerful tests can still have a substantial impact on highly suspected conditions.
* ''r<sub>i</sub>'' is the rate of probability differences leading to changes in interventions. For instance, if a medical test primarily affects the likelihood of one disease over another but both diseases have the same treatment (or no available treatment), the impact on interventions is minimal, and the test may lack value in that aspect.
* ''b<sub>i</sub>'' is the benefit of ''changes in interventions'' for the individual
* ''h<sub>i</sub>'' is the harm of such changes for the individual, including side effects of medical treatment
* ''h<sub>t</sub>'' is the harm caused by the test itself.

Several other considerations impacting the decision on whether to conduct a medical test include factors such as the test's cost, the accessibility of supplementary tests, potential interference with subsequent tests (for example, abdominal palpation inducing intestinal sounds that may disrupt abdominal auscultation), the time required for the test, and various other practical or administrative aspects. It is also essential to evaluate the potential benefits of a diagnostic test in relation to the costs associated with unnecessary tests, subsequent follow-ups, and possibly unwarranted treatment of incidental findings.<ref name="pmid12783911">{{cite journal |vauthors=Jarvik J, Hollingworth W, Martin B, Emerson S, Gray D, Overman S, Robinson D, Staiger T, Wessbecher F, Sullivan S, Kreuter W, Deyo R |title=Rapid magnetic resonance imaging vs radiographs for patients with low back pain: a randomized controlled trial |journal=JAMA |volume=289 |issue=21 |pages=2810–8 |year=2003 |pmid=12783911 |doi=10.1001/jama.289.21.2810|doi-access= |s2cid=22897506 }}</ref>

==Other clinical pathology articles==
*[[Common on-call topics]]

*[[Blood bank]]
:*[[Kleihauer–Betke test]]
:*[[Genetics questions]]
:*[[Thromboelastography]]
*[[Platelet aggregation study]]
*[[Cytology]]
*[[Microbiology]]
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