Diagnostic kits and methods configured to rapidly and non-invasively determine physiologic levels of hemoglobin. A diagnostic kit may include a chamber pre-filled with an indicator, the indicator solution including a tetramethylbenzidine (TMB) solution, the indicator being configured to change color a collection device configured to collect a test sample from a subject. The kit may also include a hemoglobin physiologic level identifier legend, the legend indicating 1) at least one color of the indicator and 2) a physiologic level and/or range of the hemoglobin and/or disease state associated with the color.
