38220090000 under HS Code DIAGNOSTIC OR LABORATORY REAGENTS ON A BACKING, PREPARED DIAGNOSTIC OR LABORATORY REAGENTS WHETHER OR NOT ON A BACKING, OTHER THAN THOSE OF HEADING 3002 OR 3006; CERTIFIED REFERENCE MATERIALS DIAGNOSTIC OR LABORATORY REAGENTS ON A BACKING, PREPARED DIAGNOSTIC OR LABORATORY REAGENTS WHETHER OR NOT ON A BACKING, OTHER THAN THOSE OF HEADING 3002 OR 3006; CERTIFIED REFERENCE MATERIALS: OTHER, 38220030000 under HS Code Others, and 84213990000 under HS Code CENTRIFUGES, INCLUDING CENTRIFUGAL DRYERS; FILTERING OR PURIFYING MACHINERY AND APPARATUS, FOR LIQUIDS OR GASES FILTERING OR PURIFYING MACHINERY AND APPARATUS FOR GASES: OTHER: OTHER were the top imported HS Codes by ANALYTICAL AND SAMPLE PREP MACHINES in 2023.