Quantitative Evaluation of Fine-Needle Aspiration

Abstract

A protocol was developed to obtain mature lymphocytes from freshly harvested tonsils by a combination of 5-, 10-, and 20- cm³ syringes and 21-, 23-, and 27-gauge needles. The cells were then suspended in Earle's balanced salt solution and counted with an automated cell counter. Cell counts for each study group was compared as a function of needle and syringe size. The range of harvested cells was 900 to 2800 cells per cubic millimeter, allowing adequate cellular material for diagnostic purposes. The amount of negative pressure for each syringes/needle combination was measured with a manometer. Pressures ranged from –500 to –700 cm of H₂O pressure. In this particular study, fine-needle aspiration with a 20-cm³ syringe and 21-gauge needle yielded the best results.