A long slide pull preparation, or pull preparation, is a variation of the T-preparation. This method results in shorter smears than the T-preparation but produces two smears for each drop of bone marrow.
In this method, a drop of bone marrow is placed in the center of a slide while a second slide is placed directly on top with as much overlap as possible. The idea is to leave only enough of the edges revealed to allow the preparer to grip the slides for the pulling of the smear. Once the bone marrow has spread toward the edges, the two slides are slowly slid apart, forming a 1-2 inch smear on both the top and bottom slides.
This method provides more smears per volume of bone marrow used but is a bit more difficult to use without regular technique practice. The placement of the drop of marrow is critical to obtaining two usable smears from each pulled smear. Pull preps can be made at the patient bedside from a syringe or from an anticoagulated bone marrow sample.
