Microalgae cultivation processes are becoming increasingly used for food and feed production and for wastewaters treatment. Large part of laboratory experiments and industrial processes are carried out with microalgae cultivated in non-aseptic environments containing biological contaminants as bacteria, fungi, viruses and grazers. Such contaminants can significantly influence microalgae growth through interactions such as competition, parasitism, predation and mutualism. Accurate and selective quantification of contaminants and microalgae in terms of cell and biomass concentration and of elemental composition is fundamental to understand how and how much such interactions affect microalgae growth and the quality of the produced biomass.

In this work a review is made about the main analytical methods that have been employed, and that might be potentially used in the future, to quantify microalgae and their biological contaminants in heterogeneous samples.

Large part of data available about biological contaminants in microalgae cultures come from cell concentration analysis or from qualitative methods.

Bacteria and grazers have been the mostly investigated contaminants, while less attention has been given to viruses and fungi. Flow cytometry and DNA analysis are two of the most powerful and promising techniques for cell concentration measurement, however relevant work is still required for protocols optimization, in particular to attain quantitative and reproducible methods.

Biomass concentration and elemental composition of contaminants inside microalgae cultures has been scarcely investigated. For this aim, different innovative techniques for single cell mass and elemental composition analysis have been described, focusing on their potential application for microalgae samples.

微藻培养方法正越来越多地用于食品和饲料生产以及废水处理。大部分实验室实验和工业过程都是在非无菌环境中种植的微藻进行的，其中含有细菌，真菌，病毒和放牧者等生物污染物。此类污染物可通过竞争，寄生，捕食和共生等相互作用显着影响微藻的生长。就细胞和生物质浓度以及元素组成而言，对污染物和微藻进行准确，选择性的定量分析对于了解这种相互作用如何以及在多大程度上影响微藻的生长以及所产生生物质的质量至关重要。

在这项工作中，对已采用的主要分析方法进行了综述，这些方法可能在将来可能用于量化非均质样品中的微藻类及其生物污染物。

关于微藻培养物中生物污染物的大部分可用数据来自细胞浓度分析或定性方法。

细菌和放牧者是研究最多的污染物，而对病毒和真菌的关注较少。流式细胞术和DNA分析是用于细胞浓度测量的两种最强大和最有前途的技术，但是仍然需要相关工作来优化实验方案，特别是要获得定量和可重现的方法。

很少研究微藻培养物中污染物的生物量浓度和元素组成。为了这个目标，已经描述了用于单细胞质量和元素组成分析的不同创新技术，重点是微藻样品的潜在应用。