US 11,738,341 B2
Dispensing of highly viscous liquids
Jenny Dittus, Walzbachtal (DE); Tobias Walz, Straubenhardt (DE); Andreas Hecht, Pforzheim (DE); Jubin Kashef, Karlsruhe (DE); and Volker Barenthin, Neulingen (DE)
Assigned to Roche Molecular Systems, Inc., Pleasanton, CA (US)
Filed by Roche Molecular Systems, Inc., Pleasanton, CA (US)
Filed on Feb. 9, 2021, as Appl. No. 17/171,989.
Claims priority of application No. 20156402 (EP), filed on Feb. 10, 2020.
Prior Publication US 2021/0245155 A1, Aug. 12, 2021
Int. Cl. B01L 3/00 (2006.01)
CPC B01L 3/502715 (2013.01) [B01L 3/502738 (2013.01); B01L 2400/0487 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A dispensing system for providing a preset small volume of liquid ≤200 μl into a filling area of a microfluidic sample carrier comprising at least one flow channel, the system including a liquid reservoir,
a liquid pump connected to the liquid reservoir,
at least one interface unit provided for each flow channel of the microfluidic sample carrier, wherein the liquid is provided to each flow channel via a respective interface unit,
a conduit member comprising a supply channel connecting the liquid pump and each interface unit,
a first valve connected to the supply channel, and
at least one second valve arranged between the supply channel and a respective interface unit,
wherein,
the first valve is a prime valve configured, when opened, to flush the supply channel with sealing liquid by pumping sealing liquid into the supply channel, wherein excessive sealing liquid potentially including air bubbles can be discharged through the open first valve,
each interface unit comprises an injector connected to the conduit member, with each injector comprising a main body and an injection channel provided in the main body,
each injection channel includes an inlet part for receiving liquid from the supply channel, an outlet part for dispensing liquid into a sample carrier liquid inlet, and a middle part for guiding liquid from the inlet part to the outlet part, with the outlet part ending in an outlet opening of the injector, and
a cross section øin of the inlet part, a cross section ømid of the middle part and a cross section øout of the outlet part, wherein each injection channel meet the following conditions:
Πout>øin; and
Πout>ømid.