Erythrina Cristagalli Lectin (ECL, ECA), Fluorescein, 5 mg. ECL has been reported to be useful for the isolation of human natural killer (NK) cells using a negative selection panning technique (protocol available upon request or on the Vector Laboratories website). Human NK cells appear to lack accessible surface carbohydrate structures required for binding ECL and, unlike other mononuclear cells, do not adhere to ECL-coated culture dishes. Since this procedure involves a negative selection panning technique, a high recovery of viable NK cells can be obtained. The adherent cells can also be recovered by incubation in galactose or lactose. Fluorescein-labeled Erythrina cristagalli lectin has an appropriate number of fluorochromes bound to provide the optimum staining characteristics for this lectin. This conjugate is supplied essentially free of unconjugated fluorochromes. Excitation max: 495 nm; Emission max: 515 nm. The recommended concentration range for use is 5–20 µg/ml.