On our own behalf: Optimizing the quality of service

It is our job to offer you the current repertoire of state-of-the-art leukemia diagnostic services in the Munich Leukemia Laboratory (MLL). To fully optimize the diagnostic process, the integrity of the sample collected is of great importance, both to provide reliable test results and to apply the requisite methods within the operating workflow. So that we may always be able to best serve you as the sender of the sample and the affected patients, we would like to explain some important aspects of the pre-analytical phase, which includes blood and bone marrow sample collection, handling and transport to the laboratory.

The quality of our diagnostic process depends on our diagnostic methods as well as the integrity of the forwarded sample.

Provision of certain basic information is very important for creating the workflow (i.e. order control) and for the final interpretation of results (particularly for initial diagnoses). In addition to a clearly formulated (suspected) diagnosis (ICD codes on their own are rarely helpful) and a clinical diagnostic question, it is essential to provide blood count details (preferably a differential hematology diagnosis). In the case of follow-up examinations, information on previous therapy is helpful. Unambiguous identification of sample material and any accompanying material (name, date of birth, EDTA or heparin) is essential.

Prolonged sample transit times create obstacles for cytomorphology (if samples need to be plated), cytogenetics (requires viable cells) and immunophenotyping. Samples for these types of tests should ideally reach us within 1-2 days. Samples for molecular genetic analyses also deteriorate if transport takes longer than 3 days.

In urgent cases, a courier service guarantees next-day delivery for biological samples. Please note that shortly before the weekends the "Saturday delivery" comment box is ticked. Our laboratory also accepts samples on Saturdays and on all public holidays (including Bavarian public holidays). It should also be noted that DHL does not currently deliver on public holidays.

When sending bone marrow, the focus is of course on obtaining an aspirate containing tissue fragments (please be sure to provide at least 5 mL in EDTA and, additionally, 5 mL in heparin). In the case of a dry tap ("punctio sicca"), a bone marrow trephine suspended in 0.9% NaCl (not formalin!) with 1,000 IU heparin is a suitable alternative; please also provide 20 mL of peripheral blood in this case.

As for anticoagulation, it must be taken into account that EDTA (or citrate) is necessary for a cytomorphologic diagnostic work-up, whereas heparin (500 IU per mL) is required for cytogenetic analyses. For a cytomorphologic analysis, it is recommended to use the first aspirate, which is most likely to contain tissue fragments. If you make smears for the cytomorphology analysis yourself, we ask you to avoid including too much blood, to avoid the smear being too "thick" and producing squeeze artifacts, and to allow for sufficient air drying time (optimally 30-60 min) before packaging and shipping.

We hope that this information will contribute to the optimal use and optimization of our diagnostic services in the best interest of your patients.