Recent advances in single cell mRNA sequencing technology such as Drop-seq (Cell, 2015) have allowed the investigation of cellular composition and processes within complex tissues. Although some fresh tissue samples are available for prospective studies, there is an abundance of archived clinical samples readily available in biobanks to investigate different biological processes. However, archived tissues are not easily amenable to tissue digestion, yielding cells with compromised integrity. An alternate method to single-cell sequencing called DroNc-seq (Nature Methods, 2017) employs the use of single nuclei. DroNc-seq takes advantage of the higher structural integrity of the nuclear membrane as compared to the cellular membrane. This permits exploration of tissues for which a viable single-cell suspension cannot be obtained, such as cardiac tissue. With growing interest in cataloguing cardiac transcriptomic data for the Human Cell Atlas Project, the need for optimized nuclei isolation protocols proves critical. Here, we develop a method for obtaining single-nucleus suspensions from snap-frozen human heart tissue for use in DroNc-seq, expanding the variety of samples from which we can obtain transcriptomic data.