Abstract: Methods for identifying a cell population secreting a biomolecule with desirable attributes are disclosed. The desirable attributes can include, for example, quantity and quality (e.g., minimal aggregation and/or desired configuration). Cell populations identified by the disclosed methods are more likely to successfully scale during production. The methods can include assessing multiple domains/binding sites of a complex biomolecule and/or the formation of aggregates by the biomolecules. Methods of assessing a secretion level for biomolecules having a wide range of molecular weights and method for enhancing loading of cells into chambers of a microfluidic device.