Here are some protocols Ive dug up this week to label lipoproteins with DiI

1. Add 1mg lipoprotein to 2 ml of sterile lipoprotein-deficient serum, and filter-sterilze using a 0.8 uM syringe filter

2. Add 50ul of DiI (3mg/ml in DMSO), and gently vortex-mix for 8 hours at 37C

3. Raise Density to 1.063 g/ml with KBr and isolate lipoproteins by ultracentrifugation at 49,000 rpm in a Beckman 50 Ti rotor at 4C for 20 hrs

4. Collect samples by aspiration from the top of the tube and dialyze against appropriate buffer, filter over a 0.8 uM filter before use

Reference - Pitas et. al - Arteriosclerosis 1981, 1: 177-185

Protocol #2

1. 0.5mg/ml lipoproteins (2mls) in PBS with 0.5% BSA, and filter-sterilze using a 0.8 uM syringe filter

2. Add 100ul of DiI (3mg/ml in DMSO), and gently vortex-mix for 8 hours at 37C

3. Raise Density to 1.006 g/ml by overlaying with PBS and isolate lipoproteins by ultracentrifugation at 49,000 rpm in a Beckman 50 Ti rotor at 4C for 20 hrs

4. Collect samples by aspiration from the top of the tube and dialyze against appropriate buffer, filter over a 0.8 uM filter before use

Reference - Fernandez-Borja, M. et. al - J. Lipid. Res. 1996, 37 :464-481

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