Diagnostic Laboratory Section

CENTRIFUGAL FLOATATION (LANE'S METHOD)

Direct centrifugal floatation or D.C.F. method (Lane’s method) - Procedure

• Follow the steps 1, 2 and 3 as mentioned in procedure for sedimentation technique. Transfer the suspension to a conical measure, fill with tap water to the top and allow settling for 30 min.
• Discard the supernatant carefully to a remaining sediment of approximately 10 ml.
• The sediment is stirred and a sample of 2 ml is poured into a centrifuge tube.
• The tube is placed in the centrifuge. With a pipette, saturated NaCl or any other floatation fluid is added until a convex meniscus stands above the top of the tube.
• The tube is centrifuged at 2000 rpm for 2-3 min.
• A thick 19 x 19 mm square cover glass is placed on the tube, ensuring that no bubble is trapped under it. The cover glass may additionally be coated with a solution of egg white / glycerol (1:1) to improve adherence of the eggs.
• Pick off the cover glass and place it on a slide and examine under a microscope by using higher magnification.