Table I.

Differences in comet assay Protocols 1 and 2

Experimental conditions	Protocol 1	Protocol 2
Layers	1. Layer: normal slide with 1% NMP	1. Layer: GelBond® films using a 12-well format (4 × 3 wells)
	2. Layer: 1:1 cells with 2.0% LMP (end concentration 1%)	2. Layer: 1:10 cells with 1.7% LMP (end concentration 1.53%)
	3. Layer: 0.5% LMP
Lysis	1. Lysis: slides in lysis buffer with 10 mM DTT, at 4°C, for 60 min	1. Lysis: gel bond films in lysis buffer at 4°C, over night
	2. Lysis: slides in lysis stock with 0.05 mg/ml proteinase K, at 4°C, for 60 min	2. Lysis: gel bond films in lysis buffer with 10 mM DTT, at 4°C, for 60 min
		3. Lysis: gel bond films in 100 mM Trizma® buffer with 4 mM lithium diiodosalicyclate, pH 7.6, at ambient temperature, for 90 min
Enzyme treatment		1 μg/ml FPG
DNA unwinding	Electrophoresis buffer pH 13.2, 20 min	Electrophoresis buffer pH 13.2, 20 min
Electrophoresis	Electrophoresis: 25 V (0.78 V/cm) and not exceeding 300 mA at 4°C for 20 min	Electrophoresis: 20 V (0.8 V/cm) and 300 mA at 8°C for 20 min
After electrophoresis	pH neutralization	pH neutralization and fixation in ethanol (>70%) for 90 min, dried and stored
	Staining: ethidium bromide	Staining: SYBRGold™

LMP, low melting point agarose; NMP, normal melting point agarose.