To verify the maturing droplet mechanism and test its generalizability, we ordered analytical standards of PSS of 4.3, 261, 453, 622, and 976 kDa molecular weight corresponding to a range in the degree of polymerization of 21 up to close to 5000 (Supporting Table ). We refer to the 4.3 kDa PSS as the "short" PSS. All others are referred to as "long" PSS. Noteworthy, all these polymers had a polydispersity index below 1.2. We used 12.3 mM peptide and combined it with 20 mM PSS (as expressed in monomer concentration) in 200 mM MES buffered water at pH 5.3. When we supplied these solutions with 75 mM EDC as fuel, the samples became measurably turbid with all PSS independent of length (Fig. ). The turbidity decayed again with time, indicating the formation of transient assemblies that scatter light. Importantly, the samples containing long PSS regained their original transparency much later than those with short PSS, e.g., after 12 minutes for short PSS and after 19 minutes for 453 kDa PSS. Moreover, confocal microscopy revealed round, micron-sized droplets for short PSS. In contrast, for all the long PSS lengths we used, we observed rugged, non-spherical agglomerates of microns in size that dissolved much later than their short PSS counterparts (Fig. ). In conclusion, the long PSS forms more solid-like coacervates that dissolve slower than the short PSS in response to fuel, which aligns with our hypothesis of droplet division-when combined, long polyanions form solid-like coacervate-based assemblies that dissolve slower than the droplets formed by the short polyanion. Excitingly, when we used mixtures of short and long PSS as the polyanion, we observed that the droplets self-divided through a similar fragmentation mechanism observed for poly-U. Specifically, we prepared droplets like the ones above but now used 25% long PSS (622 kDa) and 75% short PSS and imaged their behavior by confocal microscopy. The droplets consisting of PSS mixtures had a lifetime measured by turbidimetry of 17 minutes, i.e., between short and long PSS lifetimes. Moreover, the long-to-short PSS ratio could tune the lifetime (Fig. ). Confocal microscopy revealed that the mixed PSS droplets were spherical and could fuse, from which we conclude they were liquid (Fig. ). When we fueled the solution with 75 mM EDC, we observed the droplets' emergence and fusion in the first minutes of the reaction cycle. Toward the end of the reaction cycle, vacuoles inside the droplets appeared (Fig. ), which we previously attributed to a mechanism in which the efflux of deactivated droplet material outcompetes the influx of activated droplet material. Around the same time, we observed the first speckles inside the remaining droplet shell. These speckles were liberated and are independent droplet fragments that survived for tens of seconds until they finally dissolved (Fig. ). Using only short PSS under the same conditions showed no vacuole, speckle formation, or division (Fig. ). These findings support our hypothesis that the long PSS forms solid-like domains inside the liquid coacervate phase that dissolve slightly later than the rest of the droplet. We analyzed the PSS composition of the droplet to validate the mechanism by spinning down the droplet phase and analyzing it using gel permeation chromatography (GPC). Because of the dynamic nature of the active droplets and the long centrifugation times required, we used static droplets as a model instead. We mutated the aspartic acid of the peptide with an asparagine. This model for the activated peptide has an overall charge of +2 and is structurally similar to the activated peptide but does not hydrolyze-we refer to it as the activated peptide model. We used our previously described kinetic model to predict the concentration of the activated peptide at different time points in the reaction cycle. The solution of static droplets was then prepared with a mixture of short and long PSS, the peptide, and the model for the activated peptide. GPC showed that the droplets early in the cycle mainly comprised the short PSS. As the droplets progressed in the reaction cycle and less activated peptides became available, their composition shifted towards long, such that, after 20 minutes, the droplets were made of 80% long PSS (Fig. ). In other words, a mixture that resembles the young droplets seem to favor short PSS whereas older droplet comprises mostly long PSS.