The key decision maker is the throughput. This means how many samples you analyze at the same time. You can select the model 310 (single-capillary = 1 sample „at a time“), 3130 (4 samples at a time) or 3130xl (16 samples at a time). These sequencers are no longer available new, only refurbished. Additionally you can think of 3500 (8 samples at a time) or 3500xl (24 samples), 3730 (48 samples) and 3730xl (96 samples). We do offer service, application support, upgrades, reagents and consumables for all of them.