I am not sure which kit you are considering, but measuring hormones is not quite as simple as measuring blood glucose. You will need to account for variation within a batch of samples (within assay variation) and among assays (among different batches). It is best to analyze each sample in duplicate or triplicate and to account for this in the analyses. If it is an EIA, you will need a plate reader and some software to calculate the output. You will need some "standard unknown" that you run in each assay to verify consistency. Furthermore, you'd like to collect the saliva samples under some standardized conditions, such as first thing in the morning before eating or drinking. Samples need to collected and stored in consistent and standardized manner and then handled in a standard way. For example, each sample may be refrigerated at a fixed temperature, centrifuged to removed debris(cells, etc) and then stored frozen in common containers before assaying. Assay temperatures must be constant. You will need to use human standards and be sure that the measured amounts fall within the linear part of the standard curve. Hormone assays are fairly complex if you want to get good results.

Dear Maria,

Measuring salivary oxytocin is a controversial topic. Some labs claim they can do it, but many researchers see reasons to be cautious/skeptical. The paper cited by Renzo above is a good example; note that the study was done by Granger who founded Salimetrics. It seems reasonable to assume that if he saw some potiential the company certainly would have jumped on it!

For an overview and explanation on why certain things simply can't be measured reliably in saliva (while other substances can), see the review that I have attached and which you can download also from Research Gate:

Bosch J.A. (2014) The Use of Saliva Markers in Psychobiology: Mechanisms and Methods. Monogr Oral Sci, 24:99-108

For Oxytocin specifically see: 

McCullough et al. Neurosci Biobehav Rev. 2013 Sep;37(8):1485-92

Javor et al. Neuro Endocrinol Lett. 2014;35(6):470-3

I hope this is helpful, although perhaps not the news you were waiting for.

Dear Jack, thank you so much for the reply, this is very helpful! 

Dear Renzo, great, THANK YOU for the paper! 

Dear Jos, yes...not the answers I was expecting... : ) but better to find out NOW than too late. Thank you so much! This is really helpful! 

Enzyme Immunoassay

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2767206/

The assay techniques have gotten much better since the 2005 paper.  See these for examples of recent papers measuring salivary oxytocin:

- Salivary oxytocin mediates the association between emotional maltreatment and responses to emotional infant faces (Bhandari et al 2013)

- Salivary oxytocin increases concurrently with testosterone and time away from home among returning Tsimane’ hunters, Jaeggi et al 2015

- Elevated salivary levels of oxytocin persist more than 7 h after intranasal administration, van Ijzendoorn et al 2012

Hi Maria

I am currently looking to measure Oxytocin in Urine samples. Blood is apparently the gold standard but because my sample includes babies I am not prepared to do this. My understanding is that urine is considered to be more reliable than saliva?  

Hi, Maria,

I am also currently facing the same challenge while preparing a study. Someone also sent me this website which has some useful references related to the reliability of oxytocin analysis from saliva: 

http://www.enzolifesciences.com/ADI-900-153A/oxytocin-elisa-kit/

Hi Maria and everybody,

I also seek to measure oxytocin in saliva but to use it as a behavioural correlate. Does any of you know whether oxytocin  in saliva runs paralel to oxytocin released in the brain??

Thanks a lot,

Héctor

Dear Hector and Maria,

These has been a thread on this topic in the past. The answers and opnions somewhat. Horvat-Gordon et al. (Physiol & Behav, 2005) published a very thorough validation study and came to the conclusion it cannot be reliably measured in saliva. This conclusion is consitent with basic glandular and oral physiology: charged peptides like oxytocin do not readily difuse from blood into saliva, which is in contrast to very small and non-charged steroids like cortisol. These principles of oral physiology are reviewed by Bosch 2014 (Monogr Oral Sci, 24:99-108), which you can download from my researchgate page.

One  implication is that the oxytocin levels in saliva likely do not, or only conditionally, correlate with levels in the blood (let alone the brain), and are probably dependent on factors like saliva flow rate.

On the other hand, several labs have assessed salivary oxytocin and claim to get good results. Regretfully none of those have published systematic and detailed validation data, which makes it difficult to verify these claims.

Personally I would be very cautious: historically there have been many attempts to assess small molecules in saliva, and most have failed. Examples are catecholamines (adrenlin and noradrenlin) and more recently Nerve Growth Factor (NGF).

For example, the past years a number of studies have appeared reporting that salivary NGF correlates with psychological and physiological variables like trauma exposure, gene-polymorphismsor, BMI, or gender. Saliva NGF was also found to incerease with stress.  However, it now appears that these findings are probably void: there is virtually no NGF in saliva and the results obtained with the salivary NGF assay were due to nonspecific binding, i.e., were artifactual (see Matin 2015 PNEC, and Turner & Bosch 2016 in the upcoming issue of Psychosomatic Medicine).

Hence, to avoid embarressment later, it might be safer to hold off from measuring oxytocin in saliva until strong validation data is published. The only thorough study published thus far is negative, and also based on known facts about how saliva composition is determined it would seem unlikely that oxytocin can be assessed reliably from saliva.

I hope this is informative,

Jos

Dear Jos,

thanks so much for your answer which is most informative. It all makes perfect sense to me. Now I even doubt whether oxitocyn released into the blood is sensitive enough to be linked to a specific behaviour.

I shall get the papers you quoted and see what else I can learn.

Again, thanks a lot!!!

Héctor

Thanks for your answer Jos.